The third component that Allan experiences in this event is the conscious experience of fear.
According to the James-Lange theory of emotion, physiological arousal precedes the experience of emotion. In this case, Allan's heart pounding and trembling are examples of physiological arousal. The second component, expressive behavior, refers to the outward expression of the emotion, such as facial expressions, body language, and vocalizations.
The third component of the emotional response is conscious experience or the subjective experience of the emotion. In this case, Allan is feeling fear as a result of the noise he heard in the middle of the night. He is consciously aware of feeling afraid.
Therefore, in this event, the three components of Allan's emotional response are physiological arousal (heart pounding and trembling), expressive behavior (jumping out of bed), and conscious experience (feeling afraid).