This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: C.V.S, Subject name: Medicine
Renin plays impoant role in 
Select and explain. 
A. Renovascular hypeension, B. Malignant hypeension, C. Coronary aery disease, D. Essential hypeension'
A: Renovascular hypeension
Answer: A: Renovascular hypeension 
Explanation: Stimulation of the renin-angiotensin-aldosterone system leads to vasoconstriction, salt and water retention, sympathetic nervous system activation. This is mediated by angiotensin II, a potent constrictor of aerioles in both the kidney and the systemic circulation . Activation of the sympathetic nervous system may initially maintain cardiac output through an increase in myocardial contractility, hea rate and peripheral vasoconstriction. However, prolonged sympathetic stimulation leads to cardiac myocyte apoptosis, hyperophy and focal myocardial necrosis.renin also has an essential role in renovascular hypeension.Renovascular hypeension is another renin-mediated form of hypeension. Obstruction of the renal aery leads to decreased renal perfusion pressure, thereby stimulating renin secretion. Over time, as a consequence of secondary renal damage, this form of hypeension may become less renin dependent. ref:Harrison&;s principles of internal medicine,ed 18,pg no 2044