The auditor's next action after finding that there is an informal unwritten set of standards in the IS department is to document and test compliance with the informal standards. This is because the auditor's role is to evaluate the adequacy and effectiveness of the existing controls, regardless of whether they are formal or informal, written or unwritten. The auditor should also assess the risks and implications of having informal standards, such as lack of consistency, accountability, or traceability. The auditor should not make recommendations, postpone the audit, or finalize the audit without performing the audit procedures. References:
* CISA Review Manual (Digital Version), Chapter 2, Section 2.21
* CISA Online Review Course, Domain 1, Module 1, Lesson 12

A nondisclosure agreement (NDA) is the best way to protect an organization's proprietary code during a joint- development activity involving a third party. An NDA is a legal contract that binds the parties involved in a joint-development activity to keep confidential any information, data or materials that are shared or exchanged during the activity. An NDA specifies what constitutes confidential information, how it can be used, disclosed or protected, how long it remains confidential, what are the exceptions and remedies for breach of confidentiality, and other terms and conditions. An NDA can help to protect an organization's proprietary code from being copied, modified, distributed or exploited by unauthorized parties without its consent or knowledge. The other options are not as effective as option B, as they do not address confidentiality issues specifically. A statement of work (SOW) is a document that defines the scope, objectives, deliverables, tasks, roles, responsibilities, timelines and costs of a joint-development activity, but it does not cover confidentiality issues explicitly. A service level agreement (SLA) is a document that defines the quality, performance and availability standards and metrics for a service provided by one party to another party in a joint-development activity, but it does not cover confidentiality issues explicitly. A privacy agreement is a document that defines howpersonal information collected from customers or users is collected, used, disclosed and protected by one party or both parties in a joint-development activity, but it does not cover confidentiality issues related to proprietary code. References: CISA Review Manual (Digital Version) , Chapter 3: Information Systems Acquisition, Development & Implementation, Section 3.2: Project Management Practices.

The best reason to implement a data retention policy is to limit the liability associated with storing and protecting information. A data retention policy is a document that defines how long data should be kept by an organization and how they should be disposed of when they are no longer needed. A data retention policy should comply with the applicable laws and regulations that govern the data retention requirements and obligations of organizations, such as tax laws, privacy laws, or industry standards4. Implementing a data retention policy can help to limit the liability associated with storing and protecting information by reducing the amount of data that need to be stored and secured, minimizing the risk of data breaches or leaks, ensuringcompliance with legal or contractual obligations, and avoiding potential fines or penalties for non- compliance5. The other options are less relevant or incorrect because:
* B. Documenting business objectives for processing data within the organization is not a reason to implement a data retention policy, as it is more related to data governance than data retention. Data governance refers to the policies, procedures, and controls that define how data are collected, used, managed, and shared within an organization. Data governance helps to ensure that data are aligned with business objectives and support decision making6.
* C. Assigning responsibility and ownership for data protection outside IT is not a reason to implement a data retention policy, as it is more related to data accountability than data retention. Data accountability refers to the identification and assignment of roles and responsibilities for data protection among different stakeholders within an organization. Data accountability helps to ensure that data are handled appropriately and securely by authorized parties7.
* D. Establishing a recovery point objective (RPO) for disaster recovery procedures is not a reason to implement a data retention policy, as it is more related to data backup than data retention. Data backup refers to the process of creating copies of data that can be restored in case of data loss or corruption. Data backup helps to ensure that data are available and recoverable in case of disaster8. RPO is a measure of the maximum amount of data that canbe lost or acceptable in case of disaster9. References: Data Retention Policy - ISACA, Data Retention - ISACA, Data Governance - ISACA, Data Accountability - ISACA, Data Backup - ISACA, Recovery Point Objective - ISACA

Access to production source and object programs is the best way to ensure that effective change management is in place in an IS environment, as it prevents unauthorized or accidental changes to the production code that could affect the functionality, performance, or security of the system. Access to production source and object programs should be restricted to authorized personnel only, and any changes should follow a formal change management process that includes documentation, approval, testing, and review.
References
ISACA CISA Review Manual, 27th Edition, page 254
Change Management Best Practices for the Engineering and ...
Change Management - an overview | ScienceDirect Topics