Point out the odd one-

Options

A. Rennin
B. Secretin
C. Calcitonin
D. Oxytocin

Answer

To solve the question of identifying the odd one out from the given options: Renin, Secretin, Calcitonin, and Oxytocin, we can follow these steps:

### Step-by-Step Solution:

1. **Identify the Options**: We have four substances: Renin, Secretin, Calcitonin, and Oxytocin.

2. **Classify Each Option**:
- **Renin**: This is an enzyme that is secreted by the kidneys and is involved in the digestion of milk protein (casein) in young mammals.
- **Secretin**: This is a hormone produced by the S cells of the duodenum that stimulates the pancreas to secrete bicarbonate.
- **Calcitonin**: This is a hormone produced by the thyroid gland that helps regulate calcium levels in the blood.
- **Oxytocin**: This is a hormone produced by the hypothalamus and released by the posterior pituitary gland, involved in childbirth and lactation.

3. **Determine the Commonality**:
- Renin is an enzyme, while Secretin, Calcitonin, and Oxytocin are all hormones.

4. **Identify the Odd One Out**: Since Renin is the only enzyme among the options, it is the odd one out.

5. **Conclusion**: The answer is Renin, as it does not belong to the category of hormones like the other three options.

### Final Answer:
The odd one out is **Renin** (Option 1).