Data classification is the process of organizing data into categories based on its sensitivity, value, and risk to the organization. Data classification helps to ensure that data is protected according to its importance and regulatory requirements. Data classification also enables data owners to make informed decisions about data access, retention, and disposal.
To implement a data classification program, it is most important to formalize data ownership. Data owners are the individuals or business units that have the authority and responsibility for the data they create or use. Data owners should be involved in defining the data classification levels, assigning the appropriate classification to their data, and ensuring that the data is handled according to the established policies and procedures. Data owners should also review and update the data classification periodically or when there are changes in the data or its usage.
The other options are not as important as formalizing data ownership when implementing a data classification program. Understanding the data classification levels is necessary, but it is not sufficient without identifying the data owners who will apply them. Developing a privacy policy is a good practice, but it is not specific to data classification. Planning for secure storage capacity is a technical consideration, but it does not address the business and legal aspects of data classification.
References:
* ISACA, CISA Review Manual, 27th Edition, 2020, page 247
* Data Classification: What It Is and How to Implement It

The best indicator of the effectiveness of an organization's incident response program is the financial impact per security event. This metric measures the direct and indirect costs associated with security incidents, such as loss of revenue, reputation damage, legal fees, recovery expenses, and fines. By reducing the financial impact per security event, the organization can demonstrate that its incident response program is effective in mitigating the consequences of security breaches and restoring normal operations as quickly as possible.
Number of successful penetration tests, percentage of protected business applications, and number of security vulnerability patches are indicators of the security posture of the organization, but they do not reflect the effectiveness of the incident response program. References: ISACA Journal Article: Measuring Incident Response Effectiveness