Endocrine gland responsible for immunity is 

Options

A. Pineal
B. Thymus
C. Pituitary
D. Adrenal

Answer

**Step-by-Step Solution:**

1. **Understanding the Question**: The question asks for the endocrine gland responsible for immunity. We need to identify which of the given options plays a crucial role in the immune system.

2. **Analyzing the Options**:
- **Option A: Pineal Gland**: This gland secretes melatonin, which regulates sleep-wake cycles but is not directly involved in immunity.
- **Option B: Thymus**: This gland produces thymosine, a hormone essential for the maturation of T-lymphocytes, which are critical components of the immune system.
- **Option C: Pituitary Gland**: Known as the master gland, it releases various hormones that regulate other glands but does not directly influence immunity.
- **Option D: Adrenal Gland**: This gland secretes hormones like adrenaline that are involved in stress responses and emotional regulation, not directly in immunity.

3. **Identifying the Correct Answer**: From the analysis, the thymus gland (Option B) is responsible for the maturation of T-lymphocytes, which are vital for the immune response. Therefore, the correct answer is the thymus gland.

4. **Final Answer**: The endocrine gland responsible for immunity is the **Thymus**.

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