- **Option 1: Thymus**
- The thymus gland is located in the chest, between the lungs, and behind the sternum. ✅
- It plays a significant role in immune system development, especially during infancy and childhood.

- Option 2: Pituitary
- The pituitary gland is located at the base of the brain, below the hypothalamus.
- It is often referred to as the "master gland" because it regulates various hormones in the body.

- Option 3: Hypothalamus
- The hypothalamus is part of the brain and is located above the pituitary gland.
- It regulates vital bodily functions, including temperature and hunger.

- Option 4: Pineal
- The pineal gland is located in the brain, near the center.
- It secretes melatonin, which regulates sleep-wake cycles.

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