The kidneys in humans are part of system that performs one of the following functions.
Answer & explanation
Correct answer: option 2
The correct answer is Option (2) → Excretion
The kidneys are the main organs of the excretory system, which also has the ureters, the urinary bladder and the urethra. Each kidney has about a million tiny filtering units called nephrons, which filter the blood and remove wastes such as urea, along with extra water and salts, as urine. This removal of harmful wastes from the body is excretion.