Sentence Correction

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

Good Explanation

https://www.beatthegmat.com/q-140-1000-sc-t17584.html

The middle income families are especially hard hit because these familes can no longer afford to buy homes.

This meaning is conveyed by only B and C (using "since" and "for").

However, option B is incorrect as it uses a comma in place of a semi-colon before "furthermore". Furthermore is a conjunctive adverb (which are used to connect two clauses and usually show a sequence of cause/effect or contrast/comparison). Other examples of common conjunctive adverbs on GMAT are however, nevertheless, etc. The rule is that you must use a semicolon before the conjunctive adverb when connecting 2 independent clauses.

That leaves option C, which uses the simple conjunction "yet" and hence does not require a semi-colon.

Tough question though.