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': 'Of the following which one correlates with isovolumic contraction phase: \nSelect and explain. \nA. AV opening and aoic and pulmonary valve closure, B. AV closure and aoic & pulmonary valve opening., C. Both valves are closed, D. Both valves are open', 'role': 'user'}, {'content': 'Answer: C \nExplanation: C i.e. Both value are closed', 'role': 'assistant'}]