## **Core Concept**
Cholecystokinin (CCK) is a peptide hormone of the gastrointestinal system responsible for stimulating the digestion of fat and protein. It plays a key role in facilitating the digestion process in the small intestine.
## **Why the Correct Answer is Right**
The correct answer, , involves understanding the primary actions of CCK, which include:
- Stimulating the contraction of the **gallbladder** to release bile into the small intestine.
- Enhancing the secretion of **pancreatic juice** rich in digestive enzymes.
- Promoting the secretion of **bile** from the liver and its release into the bile duct.
- Slowing gastric emptying to allow for more efficient digestion in the small intestine.
## **Why Each Wrong Option is Incorrect**
- **Option A:** This option is actually an action of CCK; it does stimulate pancreatic enzyme secretion.
- **Option B:** This is also an action of CCK; it does cause gallbladder contraction.
- **Option D:** This too is an action of CCK; it does slow gastric emptying.
## **Clinical Pearl / High-Yield Fact**
A key clinical correlation is that CCK release is stimulated by the presence of fat and partially digested proteins in the duodenum, making it a critical regulator of the digestion process.