Mark the odd one out

Options

A. Gastrin
B. Trypsin
C. Secretin
D. Enterocrinin

Answer

### Step-by-Step Solution:

1. **Identify the Options**: The options given are gastrin, trypsin, secretin, and enterokinase.

2. **Classify Each Option**:
- **Gastrin**: This is a peptide hormone produced in the stomach that stimulates the secretion of gastric acid.
- **Trypsin**: This is a proteolytic enzyme that helps in the digestion of proteins in the small intestine.
- **Secretin**: This is a hormone secreted by the duodenum that stimulates the pancreas to release bicarbonate and digestive enzymes.
- **Enterokinase**: This is an enzyme (also known as enteropetidase) that activates trypsinogen to trypsin in the small intestine.

3. **Determine the Odd One Out**:
- Among the four options, gastrin, secretin, and enterokinase are hormones (or hormone-like substances), while trypsin is an enzyme. Therefore, trypsin is the odd one out.

4. **Conclusion**: The answer to the question "Mark the odd one out" is **trypsin**.