Somatostatin is secreted by

Options

A. Hypothalamus
B. Pituitary
C. Pineal
D. Thyroid

Explanation

### Step-by-Step Solution:

1. **Understanding Somatostatin**: Somatostatin is a hormone that plays a crucial role in inhibiting the release of several other hormones, including growth hormone and insulin.

2. **Identifying the Source**: To determine where somatostatin is secreted, we need to look at the options provided: Hypothalamus, Pituitary, Pineal, and Thyroid.

3. **Analyzing the Options**:
- **Hypothalamus**: This is a region of the brain that produces several hormones, including somatostatin.
- **Pituitary Gland**: Known as the master gland, it releases hormones but does not produce somatostatin.
- **Pineal Gland**: This gland primarily secretes melatonin, which regulates sleep cycles.
- **Thyroid Gland**: This gland produces thyroid hormones such as thyroxine, not somatostatin.

4. **Conclusion**: Based on the analysis, somatostatin is secreted by the hypothalamus.

5. **Final Answer**: Therefore, the correct answer is **Hypothalamus**.