You might notice that sometimes your pee is darker in color than other times. Remember, pee is made up of water plus the waste that is filtered out of the blood. If you don't take in a lot of fluids or if you're exercising and sweating a lot, your pee has less water in it and it looks darker. If you're drinking lots of fluids, the extra fluid comes out in your pee, and it will be lighter. During a long-distance run on a hot day, an athlete produces large quantities of sweat. As a result, the kidneys change the rate of urine production. Why is this change important? A) Decreased urine production increases the amino acids in the blood.

B) Increased urine production removes amino acids produced as a result of running.

C) Increased urine production allows more water to remain in the bloodstream.

D) Decreased urine production allows the body to conserve water.