Has risen by 30 percent

In the past ten years, the number of Americans using 90 percent of their disposable income to pay off credit card debts by 30 percent.

(A) has been rising (B) will have risen (C) was rising (D) has risen





Hi,

I'd pick D to fit in the above.

But I wonder if it's because of "be 30 percent" that A doesn't work. That is, if "by 30 percent" is deleted, then A also flies.

Correct me if I am wrong. Thanks.