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': 'True about pulmonary embolism -a) ECG shows right ventricular strain patternb) PAO2-PaO2 difference in normalc) ECG also shows typical S1Q3 T3 patternd) Not a medical emergency \nSelect and explain. \nA. a, B. bc, C. ad, D. ac', 'role': 'user'}, {'content': 'Answer: D \nExplanation: None', 'role': 'assistant'}]