A man has a BP of 160/90mmHg, proteinuria++. KUB US are equally reduced in size with smooth borders and normal pelvic calyceal system. What is the cause of hypertension in the patient?

The key is C. bilateral renal artery stenosis. [Renal artery stenosis is the narrowing of the renal arteries, most often caused by atherosclerosis or fibromuscular dysplasia. This narrowing of the renal artery can impede blood flow to the kidneys, resulting in renovascular hypertension – a secondary type of high blood pressure].