The word "inferred" makes it clear that this is an Inference question.
Inference stimuli are made up of statements from which a deduction will be made. To untangle, simply read and paraphrase the statements in the stimulus. Here, bone depletion tends to occur as humans age. For some individuals, regular weight-bearing exercise and dietary calcium can make bones thicker, denser, and stronger - the opposite of bone depletion.
Usually, the answers to Inference questions are not predictable. Proceed to the choices, keeping in mind that the answer is something that must be true from the stimulus, not just something that could or might be true.
(D) is something that can be inferred from the stimulus and is therefore correct. The stimulus says that the actions described in (D) can make bones thicker, denser, and stronger. Since bone depletion - a decrease in thickness, density, and strength of bones - is an adverse effect of aging, the actions described in (D) can indeed allow some people to avoid a deleterious effect of aging.
(A) can be eliminated because of its extreme language: "no risk." The stimulus merely said that the bones of "some" people seem to not experience depletion.
(B) is wrong because the stimulus gives no reason to believe that people who don't exercise have a high risk of bone depletion. First of all, they might take dietary calcium and do other things not mentioned in the stimulus that prevent bone depletion. Second, the stimulus says that bone depletion "tends" to occur as humans age. One might expect, at most, that people who don't exercise would have an average risk of experiencing bone depletion, not a "high risk."
(C) is incorrect because one cannot determine from the stimulus whether the methods mentioned are the most effective ways to avoid bone depletion. The stimulus only mentions these two methods, but there could very well be a more effective way!
(E)'s extreme language makes it incorrect. It can't be said from the stimulus that only weight-bearing exercise is necessary to build bone thickness, etc.
_________________
Everything will fall into place…
There is perfect timing for
everything and everyone.
Never doubt, But Work on
improving yourself,
Keep the faith and
Stay ready. When it’s
finally your turn,
It will all make sense.