Dear Friends,
Here is a detailed explanation to this question-
karlfurt wrote:
It is possible that Native Americans originally have migrated to the Western Hemisphere over a bridge of land that once existed between Siberia and Alaska.
(A) have migrated to the Western Hemisphere over a bridge of land that once existed
(B) were migrating to the Western Hemisphere over a bridge of land that existed once
(C) migrated over a bridge of land to the Western Hemisphere that once existed
(D) migrated to the Western Hemisphere over a bridge of land that once existed
(E) were migrating to the Western Hemisphere over a bridge of land existing once
A: This answer choice incorrectly uses the present perfect tense to refer to the "Native Americans" action of migrating; the present perfect tense is only used to refer to actions that ended in the past but continue to have an effect on the present. Thus, this answer choice is incorrect.
B: This answer choice incorrectly uses the past continuous tense to refer to the "Native Americans" action of migrating; the past continuous tense is only used to describe actions that were ongoing over a period of time in the past. B also breaks parallelism between " were migrating" and "existed". Thus, this answer choice is incorrect.
C: This answer choice incorrectly modifies the noun "Western Hemisphere" with the phrase "that once existed", implying that the Western Hemisphere no longer exists. Thus, this answer choice is incorrect.
D: This answer choice maintains proper tense usage and conveys the intended meaning of the sentence. Thus, this answer choice is correct.
E: This answer choice repeats the tense error seen in Option B and the error in Option C. Thus, this answer choice is incorrect.
Hence, D is the best answer choice.To understand the concept of "Present Perfect Tense on GMAT", you may want to watch the following video (~1 minute):
To understand the concept of "Simple Continuous Tenses on GMAT", you may want to watch the following video (~1 minute):
All the best!
Experts' Global Team