Review Question - QID 210990

A 38-year-old woman presents to her primary care physician after she felt dizzy during a hike at the Grand Canyon with her family. She says that the feeling of dizziness came on suddenly, though she had felt dehydrated and tired for about an hour prior to the event. She has no past medical history and does not take any drugs. She doesn't smoke and drinks sparingly. Physical exam is unrevealing, and both the basic metabolic panel and the complete blood count are unremarkable. EKG is obtained and the results are shown in Figure A. Which of the following coronary arteries supplies the structure that is most likely abnormal in this patient?