You Were Rushed to the Emergency Room an Hour Ago

Multiple Choice

You were rushed to the emergency room an hour ago, and it has been 30 minutes since the doctor stitched up the cut on your hand. Your friend is driving you home; your heart is beginning to slow, your breathing is returning to normal, and you feel relaxed for the first time since you cut your hand. The symptoms you are feeling now were produced by the

A) reticular activating system.
B) sympathetic branch.
C) parasympathetic branch.
D) somatic system.