Q. A 28 year-old woman who is in week 10 of pregnancy presents with complaint of frequent headaches. She describes them as throbbing, they tend to lateralize to the right side of the head, and when she gets them, she wants to go to a dark, quiet room to sleep. Her mother and brother both had migraine headaches. She has never been diagnosed with migraines before but she thinks that's what they are. Temperature is 36.7 (98.7 F), Blood Pressure is 130/80, Heart Rate is 72 beats/minute. Neurological examination demonstrates normal alertness, cognition, and language; normal cranial nerve examination with normal optic discs (no papilledema); normal motor power, tone, and no tremor; normal sensory exam; normal muscle stretch reflexes; and normal gait. Cardiopulmonary auscultation is normal. No masses present on abdominal examination. Which of the following medications would you recommend she start taking for the prevention of her headaches?