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
Kerley B lines are due to 
Select and explain. 
A. Carcinoma bronchus, B. Pulmonary edema, C. Lung abscess, D. Pulmonary embolism
B: Pulmonary edema
Answer: B: Pulmonary edema 
Explanation: Pulmonary oedema is usually caused by a heart condition. Other causes include pneumonia, exposure to certain toxins and drugs, and being at high elevations.
Depending 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.
Treatment generally includes supplemental oxygen and medication.