______ is a single countermeasure composed of multiple interdependent components in series that require all components to succeed if the countermeasure is to succeed.

• A. Defense in depth
• B. Weakest link
• C. Both A and B
• D. Neither A nor B

Answer: (B)

This question tests the weakest link concept. When a countermeasure is a single chain of interdependent components that must all succeed for the overall protection to work, the strength of the entire system is limited by the weakest component. If any one part fails, the whole countermeasure fails, because there’s no alternative path or redundancy built into the chain to compensate. This is different from defense in depth, which relies on multiple layers of protections that can provide backup if one layer falters; a single failure in one layer doesn’t automatically break the entire security posture. So the description best matches the idea of the weakest link: the chain is only as strong as its weakest component.