LSAT 求助

Lourdes: Dietary fiber is an important part of a healthful diet. Experts recommend that adults consume 20 to 35 grams of fiber a day.

Kyra: But a daily intake of fiber that is significantly above that recommended level interferes with mineral absorption, especially the absorption of calcium. The public should be told to cut back on fiber intake

Which one of the following, if true, most undermines Kyra’s recommendation?

(A) Among adults, the average consumption of dietary fiber is at present approximately 10 grams a day.

(B) The more a food is processed, the more the fiber is broken down and the lower the fiber content.

(C) Many foodstuffs that are excellent sources of fiber are economical and readily available.

(D) Adequate calcium intake helps prevent the decrease in bone mass known as osteoporosis.（A）

(E) Many foodstuffs that are excellent sources of fiber are popular with consumers.

请问这道题答案为什么是A？

很明显啊，L说专家建议每天20-35克，K说不要吃那么多，

A说本来吃的就只有10克左右，因此不用减少。正好反对K，其他都无关。