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': 'Dead space is increased by all, except: \nSelect and explain. \nA. Anticholinergic drugs, B. Standing, C. Hyperextension of neck, D. Endotracheal intubation', 'role': 'user'}, {'content': 'Answer: D \nExplanation: Endotracheal intubation', 'role': 'assistant'}]