Letter A is the correct answer.
According to Dr. Gewirtz, people can respond to a variety of situations through three different ways: feelings, autonomic responses and somatic responses. While feelings are subjective emotions that vary from one person to another, somatic responses are represented by facial expressions, approach or avoidance, and autonomic responses are considered to be involuntary and hormonal. In this situation, Tom's autonomic response when he encountered a bear while hiking with his friends would be represented by a pounding heart and scarce breathing.