Which of the following is a verbal sign of aggression?

A verbal sign of aggression typically involves a manner of speaking or vocal tone that conveys hostility, annoyance, or threat. In the context of this question, while the choice indicating a "clenched fist" suggests a physical expression of aggression, it is not verbal.

Verbal aggression would include raised voices, harsh tones, or threatening language, none of which are represented in the other options provided.

The choices of subtle nodding, calm speech, and quiet demeanor all indicate non-aggressive or neutral communication styles. Subtle nodding might suggest agreement or listening, calm speech implies tranquility and reason, and a quiet demeanor often reflects passivity or contemplation rather than hostility.

Recognizing verbal cues related to aggression encompasses understanding not just the volume or tone of voice but also the words chosen to convey feelings of displeasure or hostility.