A 27 year-old female presents with 5-6 headaches monthly for the past year that are described as severe, throbbing and initially unilateral. They is associated with nausea, photophobia and phonophobia. There have been no concomitant sensory or motor deficits. Her physical examination and brain MRI are normal. What treatment would be best to reduce the frequency of the headaches?
A. Sumatriptan (Imitrex)
B. Isometheptene (Midrin)
C. Propranolol (Inderal)
D. Hydrocodone (Vicodin)