This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: JIPMER 2019, Subject name: Gynaecology & Obstetrics
[{'content': 'Which of the following is a category X drug: \nSelect and explain. \nA. Itraconazole, B. Isotretinoin, C. Nitrofurantoin, D. Acyclovir', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Itraconazole - category C Isotretinoin - category X Nitrofurantoin - Category B Acyclovir - category C Category X drugs are:- Alcohol Androgen ACE inhibitors Vitamin A Tetracycline Lithium Methotrexate Valproic acid Mifepristone Danazol Isotretinoin Radioactive lodine', 'role': 'assistant'}]