According to the James-Lange theory of emotions,

A) your trembling has nothing to do with your feeling afraid.
B) you start trembling and then decide you must be afraid.
C) you feel afraid only when you stop trembling.
D) you have to feel fear of something before you can begin to tremble.

James-Lange Theory

A theory of emotion suggesting that physiological arousal precedes the experience of emotion, thus emotions are the result of the interpretation of bodily responses.

Trembling

Involuntary shaking, quivering, or trembling movements, often resulting from fear, excitement, cold, or weakness.

Afraid

Experiencing fear or apprehension.