Comprehensive and Detailed 250–300 Words Explanation From Exact Extract from Chief Information Security Officer (CCISO) Documents:

The EC-Council CCISO Body of Knowledge identifies the primary weakness of Cost Benefit Analysis (CBA) as its lack of precision. While CBA is a valuable financial decision-making tool, CCISO materials stress that it often relies on estimates, assumptions, and probability-based inputs, particularly when applied to information security risks.

Security incidents are inherently uncertain, and factors such as threat likelihood, impact magnitude, and intangible costs (reputation damage, customer trust, regulatory scrutiny) are difficult to quantify accurately. As a result, CBAs may produce results that appear mathematically sound but are based on imperfect data.

CCISO guidance emphasizes that CISOs must clearly communicate these limitations to executive leadership. A positive CBA result does not guarantee success, nor does a negative result automatically justify rejection—especially for compliance-driven or risk-critical controls.

The other options do not reflect CCISO-identified weaknesses. CBAs are widely used, applicable to investments of all sizes, and positive results do not mandate pursuit.

Therefore, the correct and CCISO-aligned answer is It is not always precise.