The original sentence incorrectly utilizes the past perfect tense in its use of “had
contributed.” The past perfect tense demands that the simple past tense also be used
in the sentence to refer to another action that occurred in the past but after the action
referred to by the past perfect tense. Here, the sentence uses the present perfect
tense “has cited” and the present participle “estimating,” but does not use the simple
past tense to refer to another action in the later past.
(A) This choice is incorrect as it repeats the original sentence.
(B) This choice is awkward in its use of the structure “Overcomplexity, increasing
mobility . . . , and poor financial planning . . .have been cited” as this structure leads
to the use of the passive voice, which is less preferable than the active voice. It is
also problematic in its use of both the past tense “estimated” and the present perfect
tense “have been cited” to refer to the recent study; the verb tenses should be
consistent in their treatment of the study.
(C) This choice incorrectly places the modifying phrase “Citing overcomplexity,
increasing mobility . . . and poor financial planning” adjacent to “less than half of
American workers,” incorrectly suggesting that it is less than half of American
workers, and not a recent study, that cites these factors as causes for a lack of
contribution to retirement plans. This choice also repeats the original verb tense error
with "had contributed."
(D) This choice repeats the original verb tense error with "had contributed."
(E) CORRECT. This choice correctly uses both the present participle (“Citing . . .”)
and the present perfect (“has estimated”) to refer to the recent study, as well as the
present tense “contribute” in reference to the study findings. The phrase “Citing
overcomplexity, increasing mobility . . . , and poor financial planning,” is correctly
used here as a modifier for “a recent study.”