Cholecystokinin is a secretion of:
Cholecystokinin is a peptide hormone of the gastrointestinal system responsible for stimulating the digestion of fat and protein. It is synthesized by the cell in the epithelium of small intestine and secreted in the duodenum. It causes the release of digestive enzymes from the pancreas and bile from the gallbladder. Thus, the correct answer is option C.