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 as entry 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 Security incident policies are out of date is a concern that may indicate a lack of alignment, review, or update of security incident processes.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 ...

Limiting the use of logs to only those purposes for which they were collected is the best way to address potential data privacy concerns associated with inadvertent disclosure of machine identifier information contained within security logs, because it minimizes the risk of unauthorized access, misuse, or leakage of personal data that may be embedded in the logs. Logs should be collected and processed in accordance with the data protection principles and regulations, such as the General Data Protection Regulation (GDPR)
12. Restricting the transfer of log files from host machine to online storage, only collecting logs from servers classified as business critical, and limiting log collection to only periods of increased security activity are not effective ways to address data privacy concerns, because they do not prevent or mitigate the potential disclosure of personal data in the logs. References: 1: CISA Review Manual (Digital Version), Chapter 5, Section 5.4.4 2: CISA Online Review Course, Module 5, Lesson 4