Why did the principles of beneficence and autonomy sometimes conflict with each other

Band cthe nucleus of the atom

So that you don't get baby's but also prevents stis such as hiv

(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!