The main purpose of PM Optimization is to improve task effectiveness. Cost reduction may result from PM Optimization, but it is not the primary technical purpose. The real objective is to ensure that preventive maintenance tasks are doing the right work against credible failure modes, at the right interval, with the right method, and with a clear value justification. Option C is not correct as the main purpose because identifying failure modes is part of the analysis input; PM Optimization uses failure-mode knowledge to evaluate whether existing PM tasks are valid, missing, excessive, duplicated, ineffective, or poorly timed. A mature PM program should prevent or detect failure in a way that reduces risk and supports asset performance. Removing unnecessary tasks is useful only if risk is still controlled; adding tasks is useful only if the task is technically effective. CRL's REM domain focuses on engineering maintenance strategy, and PM Optimization is a classic reliability-engineering activity because it connects failure behavior to maintenance tactics. ASQ's FMEA guidance supports this logic because failure modes and effects are prioritized so the organization can apply appropriate controls against risk.