Question

what stimulus causes the release of renin?
a high blood pressure
b low blood oxygen
c low blood pressure
d low blood sodium

Explanation:

Renin is an enzyme released by the kidneys. The primary stimulus for renin release is low blood pressure (or decreased blood volume), as the renin - angiotensin - aldosterone system (RAAS) is activated to increase blood pressure and volume. High blood pressure would inhibit renin release. Low blood oxygen is not a direct stimulus for renin release, and low blood sodium is not the primary stimulus for renin release (though sodium levels can interact with the RAAS, the main trigger for renin is low blood pressure).

Answer:

C. Low blood pressure