the answer is A......
it is supported by practical evidence and examples. this is the answer because he tried and tested many different ways to see what would happen so he is happy with the conclusion that what he tested is what he gets.
Passes through the kidneys and the good stuff is kept, and the other stuff is passed through leading to the bladder. The once the bladder is full enough to send the message to the brain, urine (waste) is eliminated from the body.
It’s 8•15 which is 120 kg of potatoes