This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: C.V.S, Subject name: Medicine
[{'content': 'Dicrotic notch is due to ? \nSelect and explain. \nA. AV valve closure, B. Mitral valve closure, C. Pulmonary valve closure, D. Tricuspid valve closure', 'role': 'user'}, {'content': 'Answer: A \nExplanation: dicrotic notch. : a secondary upstroke in the descending pa of a pulse tracing corresponding to the transient increase in aoic pressure upon closure of the aoic valve. -- called also dicrotic wave Ref Davidson 23rd edition pg 430', 'role': 'assistant'}]