Final answer:
The sympathetic nervous system is responsible for preparing the body for defensive action by triggering the "fight or flight" response.
Step-by-step explanation:
The sympathetic nervous system is responsible for preparing the body for defensive action. It triggers the "fight or flight" response when an individual encounters a threatening situation. This response includes an increased heart rate, dilated pupils, and inhibited digestion. For example, if a person encounters a dangerous animal, their sympathetic nervous system would prepare the body to either flee or defend themselves.