This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Inhalational Anesthetic Agents, Subject name: Anaesthesia
[{'content': 'Inhalational anesthetic agents effect on respiratory tract all true except- \nSelect and explain. \nA. The volatile anaesthetic agents relax airway smooth muscle, B. They blunt respiratory drive, C. Supress respiratory centre, D. They increases ciliary movement', 'role': 'user'}, {'content': 'Answer: D \nExplanation: Potent inhalational agents and N2O reduce ciliary movement and clearance of mucus. The inadequate clearing of mucus may result in plugging, atelectasis and hypoxia. other effects on respiratory system 1. depress respiratory centre 2. blunt hypoxic and hypercapnic drive 3. bronchodilatation 4. inhibits hypoxic pulmonary vasoconstriction', 'role': 'assistant'}]