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
An asthmatic patient is taken into the OT for removal of a tumor from colon. Which of the following anaesthetic agent is preferred in this patient? 
Select and explain. 
A. Ether, B. Ketamine, C. TCE, D. N20
B: Ketamine
Answer: B: Ketamine 
Explanation: Ventilatory drive is minimally affected by induction doses of ketamine, although rapid intravenous bolus administration or combinations of ketamine with opioids occasionally produce apnea. Racemic ketamine is a potent bronchodilator, making it a good induction agent for asthmatic patients. Ref: Butterwoh IV J.F., Mackey D.C., Wasnick J.D. (2013). Chapter 9. Intravenous Anesthetics. In J.F. Butterwoh IV, D.C. Mackey, J.D. Wasnick (Eds), Morgan&Mikhail's Clinical Anesthesiology, 5e.