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: Pediatrics
[{'content': 'Most dangerous sign in lower respiratory tract infection in children is __________ \nSelect and explain. \nA. Chest retraction, B. Tachypnea, C. Grunting, D. Abdominal breathing', 'role': 'user'}, {'content': 'Answer: C \nExplanation: Grunting\xa0⇒\xa0\nExpirating against partially closed glottis.\nIt is an attemp to maintain positive airway pressure during expiration.', 'role': 'assistant'}]