Final answer:
Cholecystokinin secretion from the intestinal wall is stimulated by the presence of proteins and fats in the small intestine, which triggers the release of pancreatic enzymes and bile to aid in lipid metabolism. So, the correct answer is option c.
Step-by-step explanation:
Cholecystokinin (CCK) is a digestive hormone primarily stimulated by the presence of proteins and fats in the small intestine. When food in the form of chyme reaches the small intestine, CCK is released from the intestinal cells in the intestinal mucosa.
This hormone plays a critical role in lipid metabolism by stimulating the release of pancreatic lipase from the pancreas and contracting the gallbladder to release bile, thus aiding in the digestion and absorption of fats present in the chyme. Additionally, CCK acts as a hunger suppressant when it communicates with the brain.
So, the correct answer is option c.