A young patient is brought in by EMS after developing a syncopal episode while waiting for the bus. In the ER, the patient has regained consciousness and the vital signs are stable. The patient is unable to provide much of a history except to state that her primary healthcare provider had started her on terfenadine for her allergies. She denies any other past medical history and has no allergies. A 12-lead ECG is done and shown below. The astute medical student highlights what he believes is the problem area. For people who develop this syndrome in response to medications, the MOST common risk factor is?
A. Age
B. Female gender
C. Use of digitalis
D. Underlying renal dysfunction