Explanation:

- The liver is the largest gland in the human body.

- It weighs about 1.4 kilograms in an average adult.

- It performs critical functions like detoxification, protein synthesis, and chemical production.

- The pancreas is also a significant gland.

- It plays a role in digestion and blood sugar regulation.

- However, it is smaller than the liver.

- The pineal gland is tiny.

- It's located in the brain and regulates sleep patterns by producing melatonin.

- The hypothalamus is a small region of the brain.

- It links the nervous system to the endocrine system and helps regulate various bodily functions.

The correct answer is Option: 3 - Liver.