You are answering a USMLE-style medical question. Question: A 26-year-old G1P0 woman presents to her primary care physician’s office with feelings of anxiety and trouble with sleep. She finds it difficult initiating sleep, occasionally has palpitations, and feels fatigued. She denies having similar symptoms in the past or starting any new medications or illicit drugs. She is currently 10 weeks pregnant and is closely followed by her obstetrician. Her temperature is 98.6°F (37°C), blood pressure is 125/70 mmHg, pulse is 105/min, and respirations are 18/min. On physical exam, the patient is mildly diaphoretic. The skin is warm and the thyroid gland is diffusely enlarged with thyroid bruits. Laboratory studies are significant for a thyroid-stimulating hormone level of 0.01 µU/mL (normal is 0.5-5.0 µU/mL) and an elevated free thyroxine (FT4) that is inappropriate for her pregnancy. Which of the following is the best treatment option for this patient? Options: A) Methimazole B) Propylthiouracil C) Radioiodine therapy D) Thyroidectomy Reply with ONLY the letter of the correct answer (A, B, C, or D). No explanation.