请教一道语法题

2.     As the housing affordability gap widens, middle-income families are especially hard-hit, and these families can no longer qualify to buy homes, and rising rental rates force them to use far more than the standard 25 percent of their incomes for housing, leaving them with no equity or tax write-offs to offset the expenditures.

(A) and these families can no longer qualify to buy homes, and

(B) since these families can no longer afford to buy homes, furthermore

(C) for these families can no longer afford to buy homes, yet

(D) and these families can no longer afford to buy homes; however,（C）

(E) and these families can no longer afford to buy homes, for

B错在何处?For可以放在句中使用吗?

1. for放在句中可以当作because用.  from Longman:

for (conj.): used to introduce the reason for something [= because]:

I cannot tell whether she is old or young, for I have never seen her.

He found it increasingly difficult to read, for his eyesight was beginning to fail.

2. 前半句讲中产阶级买不起房子; 后半句租房涨价迫使人们买房,但不能write-off. 前后有对比关系.

3. furthermore 是副词, 不能连接句子.