The correct option is C Renin
When renal blood flow is reduced, juxtaglomerular cells in the kidneys convert the prorenin present in the blood into renin and secrete it directly into circulation. Plasma renin then carries out the conversion of angiotensinogen released by the liver to angiotensin I. Angiotensin I is subsequently converted to angiotensin II by the enzyme angiotensin-converting enzyme found in the lungs. Angiotensin II is a potent vasoactive peptide that causes blood vessels to constrict, resulting in increased blood pressure.