This surveillance task is described as checking the environment using passive measures for the presence of CBRN hazards.

• A. Monitor
• B. Observe
• C. Detect
• D. Collect

Answer: (A)

Monitoring is about continuously checking the environment with measurement instruments to track conditions over time, using passive methods that don’t disturb the scene. In CBRN surveillance, this means using sensors and detectors that observe ambient conditions and log data to detect the presence of hazards as they arise or change, without actively engaging with the environment. This ongoing, passive environmental observation fits the description of a task described as checking the environment for CBRN hazards. In contrast, collecting involves gathering samples for later lab analysis, detecting is about confirming a hazard at a point in time, and observing is a more general seeing or watching that doesn’t necessarily imply continuous measurement and data recording.