Release of pancreatic juice is stimulated by

Options

A. enterokinase
B. cholecystokinn
C. trypsinogen
D. secretin

Explanation

To answer the question regarding what stimulates the release of pancreatic juice, we can follow these steps:

### Step-by-Step Solution:

1. **Understanding Pancreatic Juice**:
- Pancreatic juice is a digestive fluid produced by the pancreas. It contains enzymes that aid in the digestion of carbohydrates, proteins, and fats.

2. **Identifying Stimuli for Release**:
- The release of pancreatic juice is regulated by hormones and other factors. We need to identify which of the given options is a hormone that stimulates this release.

3. **Analyzing the Options**:
- **A. Enterokinase**: This is an enzyme that activates trypsinogen to trypsin but does not stimulate pancreatic juice release.
- **B. Cholecystokinin (CCK)**: This hormone stimulates the gallbladder to release bile and also stimulates the pancreas to release digestive enzymes, but it is not the primary hormone for stimulating pancreatic juice.
- **C. Trypsinogen**: This is an inactive enzyme (zymogen) that is converted to trypsin and does not stimulate the release of pancreatic juice.
- **D. Secretin**: This hormone is produced by the mucosa of the duodenum in response to acidic chyme entering the small intestine. It stimulates the pancreas to secrete bicarbonate-rich pancreatic juice.

4. **Conclusion**:
- The correct answer is **D. Secretin**. This hormone is crucial for regulating the volume and composition of pancreatic juice.

### Final Answer:
The release of pancreatic juice is stimulated by **Secretin**.