This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Cardiovascular system, Subject name: Physiology
[{'content': 'In a normal person which of the following occurs when he changes to supine position from standing \nSelect and explain. \nA. Cerebral perfusion increases, B. Hea rate settles to a higher level, C. Immediate increase in venous return, D. Decreased perfusion to the apex', 'role': 'user'}, {'content': 'Answer: C \nExplanation: Venous return is decreased in standing posture due to pooling of blood in lower extremities and is maximum in lying down position. Ref: Textbook of medical physiology by N Geetha, 2nd edition, page no. 170', 'role': 'assistant'}]