To my mind, the answer is C. A,D,E do not suit us because the verb provides should be provide (to be parallel to the verb establish). As for B, the words to live and work modify city planners, not population.

IMO C for parallelism,

will establish.... and (will) also provide

IMO C

pandeyvineet24 wrote:IMO C for parallelism,

will establish.... and (will) also provide

Then what is right answer? using both "As well as" with "and" makes sentence wordy.

IMO is C.
Keep it simple.
the renewal project will establish a population that lives and works downtown and also provides the office space needed to attract new businesses.

A) that lives and works downtown and also provides
"that....downtown" modifies "population. "provide" should be matched with "establish" (will is understood)
B) to live and work downtown and also provide
"the renewal project will establish to live and work? illogical. Good bye.
C) that lives as well as works downtown and also provide
Bull's eye. "as well as" and "and also" oh well, it's the best out of 5. So let's keep that way.
D) which lives as well as works downtown and also provides
"which"( non-restrictive) is so wrong. We need "that"( restrictive) "provides" is wrong.
E) who live as well as work downtown and also provides
"who"? Nope. It is not correct. "provides" is wrong.

Hope this helps.