Data disposal controls are the measures that ensure that data are securely and permanently erased or destroyed when they are no longer needed or authorized to be retained. Data disposal controls support business strategic objectives by reducing the risk of data breaches, complying with data privacy regulations, optimizing the use of storage resources, and enhancing the reputation and trust of the organization1.
A media sanitization policy is a document that defines the roles, responsibilities, procedures, and standards for sanitizing different types of media that contain sensitive or confidential data. Media sanitization is the process of removing or modifying data on a media device to make it unreadable or unrecoverable by any means. Media sanitization can be achieved by various methods, such as overwriting, degaussing, encryption, or physical destruction2.
A media sanitization policy would provide an IS auditor with the greatest assurance that data disposal controls support business strategic objectives because it demonstrates that the organization has a clear and consistent approach to protect its data from unauthorized access or disclosure throughout the data life cycle. A media sanitization policy also helps the organization to comply with various data privacy regulations, such as the EU General Data Protection Regulation (GDPR), the US Health Insurance Portability and Accountability Act (HIPAA), or the Payment Card Industry Data Security Standard (PCI DSS), that require proper disposal of personal or sensitive data3.
The other options are not as effective as a media sanitization policy in providing assurance that data disposal controls support business strategic objectives. A media recycling policy is a document that defines the criteria and procedures for reusing media devices that have been sanitized or erased. A media recycling policy can help the organization to save costs and reduce environmental impact, but it does not address how the data are disposed of in the first place4. A media labeling policy is a document that defines the rules and standards for labeling media devices that contain sensitive or confidential data. A media labeling policy can help the organization to identify and classify its data assets, but it does not specify how the data are sanitized or destroyed when they are no longer needed. A media shredding policy is a document that defines the methods and procedures for physically destroying media devices that contain sensitive or confidential data. A media shredding policy can be a part of a media sanitization policy, but it is not sufficient to cover all types of media devices or data disposal scenarios.
References:
* ISACA, CISA Review Manual, 27th Edition, 2019
* ISACA, CISA Review Questions, Answers & Explanations Database - 12 Month Subscription
* Secure Data Disposal and Destruction: 6 Methods to Follow1
* Why (and How to) Dispose of Digital Data2
* What is Data Disposition? The Complete Guide3
* Data Disposition: What is it and why should it be part of your data retention policy?

The most important issue for an IS auditor to consider with regard to Voice-over IP (VoIP) communications is the homogeneity of the network, because it affects the quality, security, and reliability of the VoIP service. A homogeneous network is one that uses a single protocol or standard for VoIP communication, such as Session Initiation Protocol (SIP) or H.32312. A homogeneous network can reduce the complexity, latency, and interoperability issues that may arise from using different or incompatible protocols or devices for VoIP communication12. Continuity of service, identity management, and nonrepudiation are also important issues for VoIP communications, but not as important as the homogeneity of the network. References: 1: CISA Review Manual (Digital Version), Chapter 4, Section 4.4.3 2: CISA Online Review Course, Module 4, Lesson 4

A compliance gap analysis is a detailed review of an organization's current state of compliance against a specific regulation or standard. It helps identify the areas and controls that are not meeting the requirements, assess their risk levels, and determine the corrective actions that can be taken to achieve compliance12. A compliance gap analysis is the most useful tool for an IS auditor to review when auditing against a new regulation, as it provides a clear and comprehensive picture of the compliance status, gaps, and remediation plan of the organization.
References
1: Information Security Architecture: Gap Assessment and Prioritization - ISACA
2: How to perform Compliance Gap Analysis? - Sprinto

The first step to successfully implement a corporate data classification program is to approve a data classification policy. A data classification policy is a document that defines the objectives, scope, principles, roles, responsibilities, and procedures for classifying data based on its sensitivity and value to the organization. A data classification policy is essential for establishing a common understanding and a consistent approach for data classification across the organization, as well as for ensuring compliance with relevant regulatory and contractual requirements.
Selecting a data loss prevention (DLP) product (option B) is not the first step to implement a data classification program, as it is a technical solution that supports the enforcement of the data classification policy, not the definition of it. A DLP product can help prevent unauthorized access, use, or disclosure of sensitive data by monitoring, detecting, and blocking data flows that violate the data classification policy.
However, before selecting a DLP product, the organization needs to have a clear and approved data classification policy that specifies the criteria and rules for data classification.
Confirming that adequate resources are available for the project (option C) is also not the first step to implement a data classification program, as it is a project management activity that ensures the feasibility and sustainability of the project, not the design of it. Confirming that adequate resources are available for the project involves estimating and securing the necessary budget, staff, time, and tools for implementing and maintaining the data classification program. However, before confirming that adequate resources are available for the project, the organization needs to have a clear and approved data classification policy that defines the scope and objectives of the project.
Checking for the required regulatory requirements (option D) is also not the first step to implement a data classification program, as it is an input to the development of the data classification policy, not an output of it.
Checking for the required regulatory requirements involves identifying and analyzing the applicable laws, regulations, standards, and contracts that govern the protection and handling of sensitive data. However, checking for the required regulatory requirements is not enough to implement a data classification program; the organization also needs to have a clear and approved data classification policy that incorporates and complies with those requirements.
Therefore, option A is the correct answer.
References:
* Data Classification: What It Is and How to Implement It
* Create a well-designed data classification framework
* 7 Steps to Effective Data Classification | CDW
* Data Classification: The Basics and a 6-Step Checklist - NetApp
* Private and confidential February 2021 - Deloitte US