This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Other topics and Adverse effects, Subject name: Anatomy
[{'content': 'Which of the following drugs is both effective and safe to use in a pregnant patient suffering from bipolar disorder? \nSelect and explain. \nA. Carbarnazepine, B. Lithium, C. Olanzapine, D. Valproic acid', 'role': 'user'}, {'content': 'Answer: C \nExplanation: (Ref: KDT 6/2 p429, 430) All of these drugs can be used for the treatment of bipolar disorder but carbamazepine, lithium and valproic acid are teratogenic. Olanzapine is safe in pregnancy.', 'role': 'assistant'}]