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Answer Osmoregulation
Explanation: the kidney is responsible for the removal of wastes and detoxify the body also but in the case of patient who have lose about 85-90 % of their kidney function, they use artificial means called Dialysis to remove this waste. Osmoregulation has to do with the kidney filtering the blood for any waste product.
D. The optimal amount of physical activity needed to maintain weight is unclear.
Yes it is very hard obtain it
