A 62-year-old man with long-standing hypertension undergoes CT angiography for evaluation of abdominal aortic atherosclerosis. The radiologist notes a calcified plaque at the level of the renal pyramid–cortex junction where vessels arch along the base of the pyramids. Reduced downstream perfusion is expected to most directly decrease blood flow through which of the following vessels next in sequence?

(Assume normal renal vascular anatomy and that the lesion is localized to the described arching vessel.)