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': 'Dicrotic notch is caused by \nSelect and explain. \nA. Closure of mitral valve, B. Opening of mitral valve, C. Closure of aoic valve, D. Opening of aoic valve', 'role': 'user'}, {'content': 'Answer: C \nExplanation: Closure of aoic and pulmonary valve causes a characteristic notch called dicrotic notch or incisura in pulse wave tracing Ref : Ganong 25th ed/page 540', 'role': 'assistant'}]