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': 'Most impoant factor determining the affect of anaesthetic agent on fetus ? \nSelect and explain. \nA. Duration of pregnancy, B. MAC, C. Protein binding, D. Route of anaesthetic', 'role': 'user'}, {'content': "Answer: A \nExplanation: Ans. is 'a' i.e., Duration of pregnancy All the given options determine the effect of anaesthetic on fetus. But, duration of pregnancy is the most impoant. Almost all anaesthetic agents can be potentially teratogenic. Day 15th to day 60 is the most critical period.", 'role': 'assistant'}]