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
All are decreased in infiltrative lung disease, Except 
Select and explain. 
A. Vital capacity, B. Alveolar arterial difference in PaO2, C. Total lung capacity, D. Lung compliance
B: Alveolar arterial difference in PaO2
Answer: B: Alveolar arterial difference in PaO2 
Explanation: None