Recent third-party IS audit reports would be most helpful in determining the effectiveness of the IT governance framework of the target company. IT governance is a framework that defines the roles, responsibilities, and processes for aligning IT strategy with business strategy. A third-party IS audit is an independent and objective examination of an organization's IT governance framework by an external auditor.
Recent third-party IS audit reports can provide reliable and unbiased evidence of the strengths, weaknesses, and maturity of the IT governance framework of the target company. The other options are not as helpful as recent third-party IS audit reports, as they may not be as comprehensive, accurate, or current as external audits. References: CISA Review Manual, 27th Edition, page 94

The major concern with the situation where security incidents are resolved and closed, but root causes are not investigated, is that vulnerabilities have not been properly addressed. Vulnerabilities are weaknesses or gaps in the security posture of an organization that can be exploited by threat actors to compromise its systems, data, or operations. If root causes are not investigated, vulnerabilities may remain undetected or unresolved, allowing attackers to exploit them again or use them asentry points for further attacks. This can result in repeated or escalated security incidents that can cause more damage or disruption to the organization.
The other options are not as major as the concern about vulnerabilities, but rather secondary or related issues that may arise from the lack of root cause analysis. Abuses by employees have not been reported is a concern that may indicate a lack of awareness, accountability, or monitoring of insider threats. Lessons learned have not been properly documented is a concern that may indicate a lack of improvement, learning, or feedback from security incidents. Security incident policies are out of date is a concern that may indicate a lack of alignment, review, or update of security incident processes.
References:
ISACA CISA Review Manual 27th Edition (2019), page 254
Why Root Cause Analysis is Crucial to Incident Response (IR) - Avertium3 Root Cause Analysis Steps and How it Helps Incident Response ...

Unauthorized code deployment presents acritical security and operational risk.
Option A (Incorrect):Whiledocumentation issuescan cause confusion, they do not directlyjeopardizesecurity or system stability.
Option B (Correct):Deploying code without authorizationbypasseschange management controls, potentially leading to security vulnerabilities, system failures, or compliance violations. This is thegreatest risk.
Option C (Incorrect):Overwriting files can cause issues but isless severethan unauthorized deployment, which may introducemalware or untested features.
Option D (Incorrect):An unresolved bug may causeperformance issues, butunauthorized deploymentposes a higher security and compliance risk.
Reference:ISACA CISA Review Manual -Domain 3: Information Systems Acquisition, Development, and Implementation- Covers change management, release processes, and risk assessment.