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: Social & Preventive Medicine
[{'content': 'Most impoant feature to diagnose severe pneumonia? \nSelect and explain. \nA. Cyanosis, B. Chest indrawing, C. Nasal flaring, D. Fast breathing', 'role': 'user'}, {'content': "Answer: B \nExplanation: Ans. is 'b' i.e., Chest indrawing The only sign for severe pneumonia is chest indrawing", 'role': 'assistant'}]