This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Respiratory system, Subject name: Medicine
ARDS is characterised by all except 
Select and explain. 
A. Decreased surfactant, B. Alveolar transudate, C. Decreased lung compliance, D. PaO2 /FiO2 < 200
B: Alveolar transudate
Answer: B: Alveolar transudate 
Explanation: In ARDS the type1 pneumocytes and alveolar capillary endothelial cells are injured leading to the loss of normally tight alveolar barrier for fluid and macromolecules. Edema fluid rich in protein accumulates in alveolar spaces leading to decrease in compliance of lung. source : Harrison 20TH edition page 2032