Which of the following is a sign that indicates respiratory arrest?

An unresponsive state is indeed a strong indicator of respiratory arrest. When a person is unresponsive, it suggests that their brain may not be receiving sufficient oxygen, which often results from inadequate or absent breathing. In respiratory arrest, the individual is unable to breathe adequately, and this can lead to unconsciousness or unresponsiveness very quickly as the body's tissues and organs are deprived of oxygen.

In this scenario, recognizing the signs of respiratory arrest is crucial because timely intervention, such as starting CPR or providing rescue breaths, can significantly affect outcomes. The unresponsive state is a clear cue that immediate action is needed, emphasizing the importance of monitoring responsiveness in emergency situations.