This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Medical Illness Complicating Pregnancy, Subject name: Gynaecology & Obstetrics
[{'content': 'Best prenatal treatment for CAH is: \nSelect and explain. \nA. Dexamethasone, B. Betamethasone, C. Prednisolone, D. Hydrocoisone', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Maternal Dexamethasone treatment is given to suppress fetal androgen overproduction and prevent virilization of female fetuses.', 'role': 'assistant'}]