The stimulus says the body can safely store trace amounts of lead, so (A) is irrelevant. Also, it doesn’t give a consequence of not taking calcium or a benefit of taking it to show why some people should take calcium supplements that contain lead rather than not take any at all.

It doesn’t matter whether someone can eliminate lead from their diet. Instead, we need an answer that highlights a negative effect of not taking calcium or a positive effect of taking it to explain why doctors recommend calcium supplements with lead over no calcium at all.

There may be many other public health concerns that cause anemia and nerve damage, but we are only concerned with lead. We need a consequence of not taking calcium or a benefit of taking it that shows why calcium supplements with lead can be better than no calcium at all.

This increases the discrepancy by giving a negative effect of taking calcium— specifically that calcium might reduce people’s ability to tolerate lead. Instead, we need a positive effect of taking calcium and/or a negative effect of not taking it.

By showing what happens when calcium intake is insufficient, (E) highlights a previously unaddressed consequence of not taking calcium and a benefit of taking it. This explains why not taking calcium can be worse overall than taking supplements with lead.