Correct Answer:
A. Hypothalamus
Hypothalamus (Option A) is the correct answer because it acts as the body\'s thermoregulatory center. It monitors body temperature and maintains homeostasis by triggering responses such as sweating, shivering, and changes in blood vessel diameter. The Cerebrum (Option B) is responsible for higher cognitive functions, memory, and voluntary movements. The Medulla oblongata (Option C) controls vital involuntary functions such as breathing, heart rate, and blood pressure. The Cerebellum (Option D) coordinates balance, posture, and voluntary muscle movements. Therefore, the hypothalamus is the part of the brain responsible for regulating body temperature.