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': 'When a person changes position from standing to lying down position , following occurs \nSelect and explain. \nA. Venous return to heart rises rapidly, B. Decrease in blood flow to the lung apex, C. Heart rate increases and settles at a higher level, D. Cerebral blood flow becomes more than that in standing position and settles at a higher level', 'role': 'user'}, {'content': 'Answer: A \nExplanation: None', 'role': 'assistant'}]