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

我认为B中的 furthermore比较对啦,为什么选C啊??大家来帮帮我吧

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

感觉since做连词有问题：

1.如果做“自从.....以来”解释的话，似乎因果关系上有问题，应该是gap widens造成families can no longer afford to buy homes。而不是自从families can no longer afford to buy homes以来gap widen

2.做“原因”解释的话，也说不通

furthermore是副词，不是连词不能通过“逗号+副词+句子”来连接两个句子吧，而yet可以是副词也可以是连词，可以连接句子