What phrase best describes an action necessary to check a potential emergency situation?

The phrase that best describes an action necessary to check a potential emergency situation is "Investigate dead body." This action is critical because the discovery of a dead body is often an immediate indicator of a serious or potentially criminal situation that requires prompt attention from law enforcement. Investigating such a scenario involves assessing the circumstances around the body, determining the cause of death, and identifying any potential evidence or witnesses that could aid in understanding the incident.

In contrast, the other options involve actions that, while relevant in their contexts, do not necessarily signify an emergency situation to the same extent. Conducting follow-up may be important for ongoing cases but does not initiate emergency response. Responding to a noise complaint can address disturbances but may not indicate a critical situation unless further evidence suggests otherwise. Inspecting a noise disturbance is similar; it is usually a preventative or investigatory measure rather than an immediate emergency response. Thus, investigating a dead body stands out as the most urgent and requisite action in terms of addressing a potential emergency.