individuals have two kidneys, but most of us need only one. people who have lost both kidneys through accident or disease must be hooked up to a dialysis machine, which cleanses waste from their bodies. say a person who has two good kidneys offers to sell one of them to someone whose kidney function has been totally destroyed. the seller asks $30,000 for the kidney, and the person who has lost both kidneys accepts the offer. a. who benefits from the deal? b. who is hurt? c. should a society allow such market transactions? why?