A patient experiences a sudden drop in blood pressure upon standing up quickly (orthostatic hypotension). Which physiological compensatory mechanism is immediately activated to help restore mean arterial pressure?

✓ Correct Answer: Option C

Orthostatic hypotension triggers the baroreceptor reflex. A decrease in blood pressure is detected by baroreceptors, leading to increased sympathetic outflow, which causes vasoconstriction and increased heart rate to restore blood pressure.