p. 92 Q.10
* 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

일단 (B), (C)는 제꼈는데 왜 (D)만 답이 되는지..
has risen과 has been rising이 어떻게 다른 거죠?
has risen도 계속적 의미로 쓰이면 has been rising하고 같은 뜻 아닌가요?
너무 헷갈리네요. 설명 부탁해요ㅜㅜ



p. 93 Q. 28
*As a temporary worker, we will notify you if a job that fits your
experience and interests ------- available.
(A) become  (B) becomes  (C) became  (D) will become

답은 (B)인데요.
원래 notify + 목적어1 + 목적어2 잖아요.
그래서 저는 문제풀 때
~ we will notify [you] [if a job that fits your experience and interests ------- available].
　　　　　　목적어1　　　　　　　　　　　목적어2
이렇게 보고 if절을 명사절 취급해서 빈 칸에 will become을 넣었거든요.
제가 틀린 건가요??