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
Which anaesthetic agent can have teratogenic effect? 
Select and explain. 
A. N2O, B. Halothane, C. Isoflurane, D. Desflurane
A: N2O
Answer: A: N2O 
Explanation: Nitrous oxide can have teratogenic effect if used for prolonged period of time.