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: Anaesthesia
[{'content': 'What should be the internal diameter of the endotracheal tube in a child weighing 1500 gm ? \nSelect and explain. \nA. 2 mm, B. 2.5 mm, C. 3 mm, D. 3.5 mm', 'role': 'user'}, {'content': 'Answer: C \nExplanation: Body weight in grams and internal diameter of ET tube :-\n< 1000 gm = 2.5 mm, 1000-2000 gm = 3 mm, 2000-3000 = 3.5 mm, > 3000 = 3.5-4.0 mm.', 'role': 'assistant'}]