Tough one. Took 2 mins to get to it. Going with C. Daagh, let me know the OA.
The growing demand for cheaper houses, unpolluted environs and tension- free lifestyle, along with the inability to pay the high rentals in down–town have turned the middle income families hunt for mortgaged houses in the suburban communities.
(A) The growing demand for cheaper houses, unpolluted environs and tension- free lifestyle, along with the inability to pay the high rentals in down–town have turned
---> Needs to be a singular verb for the noun demand. X along with Y is going to the mall. the phrase "along with" does not conjugate the nouns.(B)The growing demand for cheaper houses, unpolluted environs and tension- free lifestyle and for the inability to pay the high rentals in down–town have turned
---> awkward "for the inability". ©The growing demand for cheaper houses, unpolluted environs, tension- free lifestyle together with the inability to pay the high rentals in down–town has turned
----> the verb HAS is correct here as the phrase "together with" does not conjugate the nouns. Rest of it looks good. Going with this.(D)The growing demands for cheaper houses, unpolluted environs and tension-free lifestyle in addition to the inability to pay the high rentals in down–town is turning
---> Growing "demands" warrants a plural verb and not a singular "is". Should be "Growing demands.....are turning".(E)The growing demand for cheaper houses, unpolluted environs and tension- free lifestyles as well as the inability to pay the high rentals in down–town are turning
--> This is wrong as the phrase "as well as" does not conjugate two nouns and therefore the use of "....are turning" should be "...is turning"... refer https://grammar.ccc.commnet.edu/grammar/sv_agr.htm (point no.3 in this).