This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: All India exam, Subject name: Medicine
[{'content': 'C wave in JVP is DUE TO \nSelect and explain. \nA. Bulging of tricuspid valve during the isovolumetric contraction phase, B. Atrial systole, C. Passive filling ventricle, D. Atrial relaxation', 'role': 'user'}, {'content': 'Answer: A \nExplanation: ref : rhagawa rao cardiology', 'role': 'assistant'}]