This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Endocrinology, Subject name: Physiology
[{'content': 'Siuins are associated with \nSelect and explain. \nA. Memory, B. Vision, C. Metabolism, D. Olfaction', 'role': 'user'}, {'content': "Answer: C \nExplanation: Siuins are a family of proteins that play a role in aging by regulating cellular health. They're responsible for critical biological functions like DNA expression and aspects of aging. However, siuins can only function in the presence of NAD+, nicotinamide adenine dinucleotide, a coenzyme found in all living cells Ref: guyton and hall textbook of medical physiology 12 edition page number:534,535,536", 'role': 'assistant'}]