单项选择题
A 70-year-old man seeks medical attention because of shortness of breath on minimal exertion. A posteroanterior chest radiograph reveals blunting of the right costophrenic sulcus interpreted as a right-sided pleural effusion. The aspirated fluid is straw colored and clear. The protein concentration is low, and the specific gravity is 1.011. Microscopic examination reveals an occasional mesothelial cell. Which of the following is the most likely cause of the effusion?
A.Decreased oncotic pressure
B.Left ventricular heart failure
C.Mesothelioma
D.Pneumonia
E.Tuberculosis