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': 'Not seen in primary pulmonary hypertension \nSelect and explain. \nA. Left parasternal heave, B. Right parasternal heave, C. Single S2, D. Pulmonary ejection click', 'role': 'user'}, {'content': 'Answer: B \nExplanation: None', 'role': 'assistant'}]