Due to ongoing instability in the real estate market, many people
that might at one time have bought homes as young adults are choosing to forgo such purchases in favor of living in rented accommodations.
(A) that might at one time have bought homes as young adults
(B) that as young adults might once have bought homes
(C) who might once have bought homes in young adulthood
(D) who in young adulthood might have at one time bought homes
(E) who, when they were young adults, might at one time have bought homes
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Meaning is important in solving the question. Let's take a look at answer choice one by one.
A- In Gmat , using ''that'' to refer to people is not accepted. So, drop this answer choice.
B - the same mistake as in A.
C - ''who'' correctly refers to people. Sentence gives logical meaning. Hold on this choice.
D- using ''at one time'' between two verbs does not sounds natural, but Gmat doesnt care the sound. Anyways, lets hold this one too.
E - ''who,when they were...'' when is used to refer to a time , but there is not an appropriate noun to be modified by ''when'' - drop this choice.
So, between C and D.
''At one time'' is wordier than '' once'' and answer choice C is better than D.
C is our winner.