Comprehensive and Detailed Step-by-Step Explanation:
Theprimary roleof an internalIS audit functionis to provideindependent assuranceonrisk management, internal controls, and governance processes.
* Option A (Incorrect):While audits may identifycontrol improvements, they donot initiate changes; management is responsible for implementation.
* Option B (Incorrect):Compliance audits arepartof IS auditing, but the main focus isassurance on risk and controls, not just compliance.
* Option C (Incorrect):Best practices and standards reviews are useful, but theydo not definethecore objectiveof an internal audit.
* Option D (Correct):The internal audit function'smain goalis toassess and assurethe effectiveness of an organization'srisk management and internal controls.
Reference:ISACA CISA Review Manual -Domain 1: Information Systems Auditing Process- Coversaudit objectives, assurance functions, and risk management.

Comprehensive and Detailed Explanation:
Earned Value Analysis (EVA) provides a quantitative measure of project progress by comparing planned value, earned value, and actual costs. This gives insight into schedule and budget performance, making it the best tool to assess whether the project is on track.
* Critical path (A): Helps in identifying dependencies but not progress.
* Work breakdown structure (C): Defines scope but does not measure progress.
* Traceability matrix (D): Ensures requirements coverage, not schedule/cost progress.
# ISACA Reference: CISA Review Manual 27th Edition, Domain 3 (Information Systems Acquisition, Development, and Implementation), section on project management metrics and monitoring techniques.

In reviewing the IT strategic plan, the IS auditor should consider whether it identifies the major IT initiatives that are aligned with the organization's vision, mission, and objectives, and that support the business strategy and priorities12. The major IT initiatives should also be realistic, measurable, and achievable, and should have clear timelines, budgets, and responsibilities34.
References
1: IT Strategy Template for a Successful Strategic Plan | Gartner2 2: IT Strategy Template for a Successful Strategic Plan | Gartner4 3: Conduct a Strategic Plan Review & Assessment - Governance3 4: Time To Conduct A Strategy Review? Here's How To Get Started1