A service level agreement (SLA) is a contract between a service provider and a customer that defines the expected level of performance, risks, and capabilities of an IT infrastructure. An IS auditor can use an SLA to measure how well the IT infrastructure meets the business needs and objectives, as well as to identify any gaps or issues that need to be addressed. The other options are not directly related to measuring the performance, risks, and capabilities of an IT infrastructure. References:
* CISA Review Manual (Digital Version), Chapter 5, Section 5.2.11
* CISA Review Questions, Answers & Explanations Database, Question ID 203

The best way to prevent data leakage from a lost mobile device is data encryption on the mobile device. Data encryption is a technique that transforms data into an unreadable format using a secret key or algorithm. Data encryption protects data from unauthorized access or disclosure in case of loss or theft of a mobile device.
Complex password policy for mobile devices, triggering of remote data wipe capabilities, and awareness training for mobile device users are useful measures to enhance data security on mobile devices, but they do not prevent data leakage as effectively as data encryption. A complex password policy can be bypassed by brute force attacks or password cracking tools. Remote data wipe capabilities depend on network connectivity and device power availability. Awareness training for mobile device users can reduce human errors or negligence, but it cannot guarantee compliance or behavior change. References: CISA Review Manual (Digital Version): Chapter 5 - Information Systems Operations and Business Resilience

The best document for an IS auditor to use in detecting a weakness in segregation of duties is a process flowchart. A process flowchart is a diagram that illustrates the sequence of steps, activities, tasks, or decisions involved in a business process. A process flowchart can help detect a weakness in segregation of duties by showing who performs what actions or roles in a process, and whether there is any overlap or conflict of interest among them. The other options are not as useful as a process flowchart in detecting a weakness in segregation of duties, as they do not show who performs what actions or roles in a process. A system flowchart is a diagram that illustrates the components, functions, interactions, or logic of an information system. A data flow diagram is a diagram that illustrates how data flows from sources to destinations through processes, stores, or external entities. An entity-relationship diagram is a diagram that illustrates how entities (such as tables) are related to each other through attributes (such as keys) in a database. References: CISA Review Manual (Digital Version), Chapter 3, Section 3.2

The first thing that an IS auditor should do when management responses to an in-person internal control questionnaire indicate a key internal control is no longer effective is to ascertain the existence of other compensating controls. Compensating controls are alternative controls that provide reasonable assurance of achieving the same objective as the original control. The IS auditor should verify whether there are any compensating controls in place that can mitigate the risk of the key control being ineffective, and evaluate their adequacy and effectiveness. The other options are not the first steps, because they either require more information about the compensating controls, or they are actions to be taken after identifying and assessing the compensating controls. References: CISA Review Manual (Digital Version)1, Chapter 2, Section 2.2.3

The greatest risk associated with security patches being automatically downloaded and applied to production servers is that patches may result in major service failures, as they may introduce new bugs, conflicts, or incompatibilities that could affect the functionality, performance, or availability of the servers12. Automatic patching may also bypass the testing and validation processes that are necessary to ensure the quality and reliability of the patches34.
References
1: Do you leave Windows Automatic Updates enabled on your production IIS server? - Server Fault1 2:
Azure now installs security updates on Windows VMs automatically3 3: Server Patch Management | Process of Server Patching - ManageEngine2 4: Windows Security Updates | Microsoft Patch Updates Guide - ManageEngine4