A risk register provides the MOST comprehensive insight into ongoing threats facing an organization. This is because a risk register is a document that records and tracks the identified risks, their likelihood, impact, mitigation strategies, and status. A risk register helps an organization to monitor and manage the threats that could affect its objectives, assets, and operations. A risk register also helps an organization to prioritize its response efforts and allocate its resources accordingly.

The greatest inherent risk when performing a disaster recovery plan (DRP) test is disruption to the production environment. A DRP test involves simulating a disaster scenario to ensure that the organization's plans are effective and that it is able to recover from an incident. However, this involves running tests on the production environment, which has the potential to disrupt the normal operations of the organization. This inherent risk can be mitigated by running tests on a non-production environment or by running tests at times when disruption will be minimized.

Results from a gap analysis would provide the most useful information for planning purposes when preparing an action plan to achieve compliance with local regulatory requirements by an established deadline. A gap analysis is an assessment of the difference between an organization's current state of compliance and its desired level or standard. It is a process used to identify potential areas for improvement by comparing actual performance with expected performance. A gap analysis can help to prioritize the actions needed to close the gaps and comply with the regulatory requirements, as well as to estimate the resources and time required for each action1. The other options are not as useful as results from a gap analysis for planning purposes when preparing an action plan to achieve compliance with local regulatory requirements by an established deadline. Deadlines and penalties for noncompliance are important factors to consider, but they do not provide information on how to achieve compliance or what actions are needed2. Results from a business impact analysis (BIA) are useful for identifying the critical processes and assets that need to be protected, but they do not provide information on how to comply with the regulatory requirements or what actions are needed3. An inventory of security controls currently in place is useful for assessing the current state of compliance, but it does not provide information on how to comply with the regulatory requirements or what actions are needed4. Reference: 3: Business impact analysis (BIA) - Wikipedia 2: Compliance Gap Analysis & Effectiveness Evaluation | SMS 1: What is Gap Analysis in Compliance | Scytale 4: Gap Analysis & Risk Assessment - Riddle Compliance