Melatonin is secreted by

Options

A. pineal
B. pituitary
C. thymus
D. adrenal cortex

Answer

**Step-by-Step Solution:**

1. **Identify the Hormone**: The question asks about the secretion of melatonin, which is a hormone involved in various physiological processes.

2. **Locate the Source**: Melatonin is specifically secreted by the pineal gland. This gland is located in the brain and plays a crucial role in regulating sleep-wake cycles and other biological rhythms.

3. **Understand the Function**: The primary function of melatonin includes regulating sleep patterns and influencing reproductive hormones. It can also affect skin color in some animals.

4. **Analyze the Options**: The options provided are:
- A) Pineal gland
- B) Pituitary gland
- C) Thymus
- D) Adrenal cortex

5. **Select the Correct Answer**: Based on the information, the correct answer is A) Pineal gland, as it is the gland responsible for the secretion of melatonin.

**Final Answer**: Melatonin is secreted by the pineal gland.

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