Solved by a verified expert:Multiple choice and needs to be backed up with factual information on why you chose the answer. I will not choose you as a best answer if you do not provide all information asked. PLEASE NO *WORKING ON YOUR ANSWER* REPLIES I WILL REPORT THEM*.1. Peristalsis in the small intestine beginsa. When CCK is releasedb. When chyme enters the duodenumc. When most nutrients have been absorbedd. With cephalic phase of stomach activity2. Protective collections of lymphocytes and macrophages occur in?a. the gastric pitsb. the intestinal cryptsc. the peyers patchesd. the muscularis externa3. A component of the electron transports system is?a. ironb. magnesiumc. cobaltd. zinc