求一道應該很簡單的題

The Environmental Protection Agency frequently puts mandatory controls on toxic substances that present as little risk as one in a million chances to cause cancer.

A. as little risk as one in a million chances to cause

B. as little risk as one chance in a million of causing

C. as little risk as one chance in a million that it will cause

D. a risk as little as one chance in a million for causing

E. a risk as little as one chance in a million for it to cause

題中 as little risk as one .....

跟    a risk as little as one....

有什麼分別嗎??且  這提要怎麼解阿??

原句： toxic substances that present as little risk as one in a million chances to cause cancer.

此题是在做宾语比较，两种形式：as little risk as one 和 a risk as little as one 都可以。

但是请注意句子的主语substances 是复数，用substances present a risk 是不是不太好呢？

Open to discuss....