This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Chemotherapy, Subject name: Pharmacology
[{'content': "Thalidomide used for multiple myeloma is \nSelect and explain. \nA. Assosciated with diarrhea, B. Characterised by enantiomeric interconvesions, C. Metabolized extensively by hepatic CYP system, D. Safe for use in pregnant female's", 'role': 'user'}, {'content': 'Answer: B \nExplanation: Refer Katzung 10th/919 Thalidomide used for morning sickness but later withdrawn due to teratogenic effects It is not extensively metabolized by microsomal enzymes It is now used for multiple myeloma It can also result in constipation ,peripheral neuropathy', 'role': 'assistant'}]