Okay. So activation of the sympathetic nervous system leads to a decrease in glomerular filtration rate. Why is decreasing GFR advantageous in potentially stressful, dangerous, or arousing situations? Let's run through our answers and see what we have here.
So A reads that by reducing glomerular filtration rate, the body prevents hypertension. That's actually not true at all. It's actually the opposite of how it works. So if we decrease glomerular filtration rate, we are retaining fluid. And over time, if there's a chronic decrease in filtration rate, that fluid retention can actually cause hypertension, not prevent it. So A is definitely out and that is incorrect also.
B is by increasing fluid loss, it makes you lighter in case you have to run away from danger. Tempting, given that whole fight or flight idea. However, decreasing glomerular filtration rate would not increase fluid loss. We're basically putting urine production on hold right now. We are not increasing it. So B is also out.
C reads, it helps minimize fluid loss and preserve the blood volume and blood pressure at vital organs, and that is absolutely correct. So if you were in a fight or flight situation, making urine is just not a priority, and this allows you to retain any fluids that could be essential if you were to become dehydrated, for example. It helps you preserve blood volume and pressure at important organs like your brain and your heart. Our answer is probably C.
Let's just check D. D reads, It actually is not advantageous but is a leftover quirk of evolution, and that is not true for the reason I just explained. So our answer here is going to be C.