Global sensors providing surveillance, warning, and assessment of nuclear detonations.

• A. Spacelift
• B. Space Control
• C. Al-Qa'ida Affiliates
• D. Nuclear Detonation Detection

Answer: (D)

Global sensors for detecting nuclear detonations form a dedicated monitoring network that continuously watches the world for nuclear explosions and provides timely warnings and post-event assessment. This system combines multiple sensor types—seismic sensors to catch underground tests, infrasonic sensors for large air blasts, hydroacoustic sensors for underwater tests, radionuclide sensors for released particles, and space-based observations—to locate where a detonation occurred, estimate its size, and rapidly inform decision-makers. The goal is real-time surveillance, early warning, and accurate assessment to support deterrence and treaty verification. The other options don’t describe this specialized detection network: spacelift is about placing payloads into space, space control covers managing activity in space, and Al-Qa’ida Affiliates is not a capability or system.