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': 'Primary pulmonary hypertension has following features on ECG except - \nSelect and explain. \nA. Sinus tachycardia, B. ST elevation, C. Increased Pwave amplitude, D. Right axis deviation', 'role': 'user'}, {'content': 'Answer: B \nExplanation: None', 'role': 'assistant'}]