The correct answer is A.filtering wastes from the blood.
The kidney has many important functions in the body. Most of them have to do with bodily fluids and waste. It filters about 123 to 150 quarts of blood per day and produces 1 to 2 quarts of urine per day.
B. is incorrect because does not defend or fight other organisms.
C. is incorrect because the kidney does not digest anything whatsoever.
D. is incorrect because the kidney does not transport any nutrients anywhere.
