This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: General anaesthesia, Subject name: Anaesthesia
[{'content': 'Most potent bronchodilator among inhalational anesthetic agent is \nSelect and explain. \nA. Isoflurane, B. Halothane, C. Sevoflurane, D. Desflurane', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Halothane is considered a potent bronchodilator, as it often reverses asthma-induced bronchospasm. This action is not inhibited by b-adrenergic blocking agents. Halothane attenuates airway reflexes and relaxes bronchial smooth muscle by inhibiting intracellular calcium mobilization. Halothane also depresses clearance of mucus from the respiratory tract (mucociliary function), promoting postoperative hypoxia and atelectasis. Morgan clinical anesthesia 5e pg: 16', 'role': 'assistant'}]