- A Liver
- B Pancreas (beta cells)
- C Adrenal gland
- D Pituitary gland
Correct answer: B. Pancreas (beta cells)
Explanation: Insulin is produced by beta cells of the Islets of Langerhans in the pancreas. It lowers blood glucose levels.
Concept context
The endocrine glands, hormone classification and mechanism of action, and negative feedback regulation.