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

my doubt :how do i decide between "a risk as little" and "as little risk as" .also how do we decide between "of causing" / "to cause" / "for causing"