This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: All India exam, Subject name: Medicine
[{'content': "Westermark's sign, Hampton's hump, Palla's sign are all features of which condition on chest X-ray \nSelect and explain. \nA. Tubercular pleural effusion, B. Pulmonary Embolism, C. Acute Pulmonary adema, D. Left ventricular failure", 'role': 'user'}, {'content': "Answer: B \nExplanation: A normal or nearly normal chest x-ray often occurs in PE. Well-established abnormalities include focal oligemia (Westermark's sign), a peripheral wedged-shaped density above the diaphragm (Hampton's hump), and an enlarged right descending pulmonary aery (Palla's sign).Harrison 19e pg: 1633", 'role': 'assistant'}]