A patient with a history of chronic foot and calf cramping undergoes a battery of noninvasive vascular tests. The results demonstrate an ankle-brachial index of 1.34, coupled with a Doppler finding of a single "long swoosh" sound on auscultation. Which of the following is the most likely etiology?
A.Atherosclerosis
B.Distal embolic disease
C.Multilevel occlusive disease
D.Mönckeberg's medial sclerosis