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: Unknown
[{'content': 'Pallas sign seen in \nSelect and explain. \nA. Sarcoidosis, B. Emphysema, C. Pulmonary embolism, D. Myeloma', 'role': 'user'}, {'content': 'Answer: C \nExplanation: Chest radiograph signs in PE are ,\nPallas sign – enlarged right descending pulmonary artery Hamptons hump- wedge shaped density above diaphragm Westermark sign- focal oligemia.', 'role': 'assistant'}]