Final answer:
An increase in smooth muscle activity along the GI tract is NOT likely to occur when the sympathetic nervous system is stimulated in a frightening situation.
Step-by-step explanation:
If Michael experiences a frightening situation that causes the stimulation of his sympathetic nervous system, the response NOT likely to occur is An increase in smooth muscle activity along the GI tract. This is because the activation of the sympathetic nervous system typically leads to a decrease in digestive activity as the body prioritizes other functions that are more essential for immediate survival. Key functions that are triggered include pupil dilation, an increase in heart rate and blood pressure, and the mobilization of energy reserves by converting glycogen to glucose for muscle use. Conversely, the smooth muscles of the gastrointestinal (GI) tract slow down, which may result in a feeling of 'butterflies' in the stomach due to reduced digestive processes.