Final answer:
When renin and angiotensinogen react together, it leads specifically to the conversion of angiotensin I to angiotensin II, although it ultimately contributes to increased blood pressure and vasoconstriction.
Step-by-step explanation:
When renin and angiotensinogen react together, the sequence leads to the conversion of angiotensin I to angiotensin II. Renin, which is secreted by the juxtaglomerular complex of the kidney, acts on angiotensinogen to form angiotensin I. This molecule is then converted to angiotensin II by Angiotensin-Converting Enzyme (ACE). The angiotensin II then stimulates the adrenal glands to release aldosterone, which promotes sodium reabsorption, and Antidiuretic Hormone (ADH), which increases water reabsorption. Ultimately, this increases blood pressure and causes vasoconstriction. However, among the options provided, the correct choice is A) Conversion of angiotensin I to angiotensin II as it is the direct result of the interaction between renin and angiotensinogen.