This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Physiology
[{'content': 'Biological clock of brain is located in \nSelect and explain. \nA. Preoptic nucleus, B. Lateral nucleus, C. Suprachiasmatic nucleus, D. Supraoptic nucleus', 'role': 'user'}, {'content': "Answer: C \nExplanation: Ans. is 'c' i.e., Suprachiasmatic nucleus", 'role': 'assistant'}]