You are answering a USMLE-style medical question. Question: A 32-year-old woman comes to the physician because of fatigue, breast tenderness, increased urinary frequency, and intermittent nausea for 2 weeks. Her last menstrual period was 7 weeks ago. She has a history of a seizure disorder treated with carbamazepine. Physical examination shows no abnormalities. A urine pregnancy test is positive. The child is at greatest risk of developing which of the following complications? Options: A) Renal dysplasia B) Meningocele C) Sensorineural hearing loss D) Vaginal clear cell carcinoma Reply with ONLY the letter of the correct answer (A, B, C, or D). No explanation.