What are the three zones in defense in depth?

• A. Perimeter, interior, secure core
• B. Prevention, detection, recovery
• C. Plan, act, recover
• D. Assessment, warning, threat

Answer: (D)

Defense in depth is about protecting assets through layers and turning knowledge into timely action. In this framing, the three zones represent a progression: first, you perform an assessment to understand what you’re protecting and where gaps exist. This helps you know what to monitor and what controls to put in place. Second, you establish warning, using sensors, logs, and alerts to signal when something unusual or risky is happening. This keeps you informed so you can respond quickly. Third, you address the threat itself, implementing defenses to counter or contain the activity and then recover from the impact. Framing defense in depth as assessment, warning, and threat emphasizes turning risk analysis into real-time monitoring and decisive action, which is why this option aligns with that approach.