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: Pathology
[{'content': 'The following is not characterstic of ARDS ? \nSelect and explain. \nA. Dyspnoea, B. Ability to maintain Pa02 on 100% oxygen, C. Bilateral crepts, D. Bilateral opacities on X-ray', 'role': 'user'}, {'content': "Answer: B \nExplanation: Ans. is 'b' i.e., Ability to maintain PaO, on 100% oxygen", 'role': 'assistant'}]