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: Medicine
[{'content': "'C' wave in JVP is due to - \nSelect and explain. \nA. Atrial contraction, B. Tricuspid valve bulging into right atrium, C. Right atrial filling, D. Rapid ventricular filling", 'role': 'user'}, {'content': 'Answer: B \nExplanation: None', 'role': 'assistant'}]