Which of the following is a sign of an airway obstruction?

The inability to breathe is a clear and critical sign of an airway obstruction. When the airway is blocked, the individual cannot get enough air into their lungs, leading to a life-threatening situation. This can manifest as choking, where the person may become distressed, unable to produce sounds, and can quickly deteriorate into unconsciousness if the obstruction is not resolved.

In contrast, being able to talk, coughing forcefully, and even extreme agitation can indicate other conditions or mild obstruction where the airway is not completely blocked. For instance, if a person is able to talk, it suggests that their airway remains open enough to allow for airflow. Similarly, forceful coughing might indicate that the person is still able to manage the obstruction to some extent and is attempting to clear their airway. Extreme agitation can occur for various reasons, including anxiety or panic, not solely related to airway issues. Thus, the clear indicator of an obstruction is the inability to breathe.