Which statement defines monitor in CBRN reconnaissance?

• A. Checking the environment passively for hazards.
• B. Observing a site visually.
• C. Warning others of hazards.
• D. Reporting hazards to authorities.

Answer: (A)

Monitoring in CBRN reconnaissance means continuous, passive surveillance of the environment to spot hazards as they appear. It involves keeping watch with the senses and with sensing equipment to detect chemical, biological, radiological, or nuclear threats without actively manipulating the scene. This ongoing observation provides early warning and situational awareness while minimizing exposure. The statement that describes checking the environment passively for hazards matches this idea precisely, since it emphasizes ongoing surveillance rather than taking active measurements, warnings, or reporting. Observing a site visually, warning others, and reporting hazards are related actions in the broader process, but they describe separate tasks from the passive monitoring focus.