Final answer:
The critical function of the safety officer is to monitor emergency responders for signs of stress and anxiety to ensure their well-being and maintain the efficiency of emergency operations.
Step-by-step explanation:
A critical function of the safety officer is to monitor emergency responders for signs of stress and anxiety (B). This is important because emergency responders often face high-pressure situations that can cause emotional and psychological strain. By monitoring their mental well-being, the safety officer can ensure that they receive the necessary support and intervention if needed. This helps maintain the overall effectiveness and efficiency of emergency operations.