Which of the following is NOT a character The cardiovascular system, which transports blood through the body, is a one-way system.

Its simple its a because they are more fat

Your answer is going to be c. 

(a) is not correct because one does not get increased cholesterol  from lifting weights.(b) is not correct because lifting weights cannot reduce the risk of a hereditary disease.(c) is not correct because back pain isn't a benefit! and plus, if he lifts weights properly, he should not have back pain.(d) is the correct answer because his ligaments will gain mass, making it easier for him to carry heavier weights and he will also be stronger!

Your answer is c- spermicides!