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': 'Kerley B lines are due to \nSelect and explain. \nA. Carcinoma bronchus, B. Pulmonary edema, C. Lung abscess, D. Pulmonary embolism', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Pulmonary oedema is usually caused by a heart condition. Other causes include pneumonia, exposure to certain toxins and drugs, and being at high elevations.\nDepending on the cause, pulmonary oedema symptoms may appear suddenly or develop over time. Mild to extreme breathing difficulty can occur. Cough, chest pain and fatigue are other symptoms.\nTreatment generally includes supplemental oxygen and medication.', 'role': 'assistant'}]