This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Nervous System, Subject name: Physiology
Site of central of circadian rhythm is- 
Select and explain. 
A. Supraoptic nucleus, B. Paraventricular nucleus, C. Suprachiasmatic nucleus, D. Premamillary nucleus
C: Suprachiasmatic nucleus
Answer: C: Suprachiasmatic nucleus 
Explanation: Ans. is 'c' i.e., Suprachiasmatic nucleus * Suprachiasmatic nucleus of hypothalamus regulates circadian rhythms.