please help if you know the answer. IF you could also explain it that would be very helpful but you don't need to as long as you know the answer

Remove waste material, maintaining salt, pH and water balance in the body.

Explanation:

The main function of execratory system is to remove waste material, maintaining salt, pH and water balance in the body. Kidney filters the blood and removes waste material such as urea and nitrogenous waste etc, excess amount of salts and water from the body. It also maintains pH of the body by excretion of hydrogen ions as dihydrogen phosphate or ammonia from the blood and production or reabsorption of bicarbonate ions. So we can conclude that execratory system eliminates waste material, maintaining salt, pH and water balance in the body.

c.more precipitation,but only when emission levels.