This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Miscellaneous, Subject name: Anaesthesia
[{'content': "Respiratory obstruction in comatose patients is usually due to \nSelect and explain. \nA. Presence of airway, B. Presence of Ryle's tube, C. Tracheostomy, D. Falling back of tongue", 'role': 'user'}, {'content': 'Answer: D \nExplanation: (D) Falling back of tongue# Falling back of tongue results the Respiratory obstruction in comatose patients', 'role': 'assistant'}]