Salt deposits and moisture threaten to destroy the Mohenjo-D

[aspirant2011]

Salt deposits and moisture threaten to destroy the Mohenjo-Daro excavation in Pakistan, the site of an ancient civilization that flourished at the same time as the civilizations in the Nile delta and the river valleys of the Tigris and Euphrates.

(A) that flourished at the same time as the civilizations
(B) that had flourished at the same time as had the civilizations
(C) that flourished at the same time those had
(D) flourishing at the same time as those did
(E) flourishing at the same time as those were

[spoiler]OA: What's wrong with option B??????? both the civilizations existed at the same time therefore, I felt that usage of had won't do any harm. Please explain the reasoning why is B wrong...........[/spoiler]

[bubbliiiiiiii]

Salt deposits and moisture threaten to destroy the Mohenjo-Daro excavation in
OA: What's wrong with option B??????? both the civilizations existed at the same time therefore, I felt that usage of had won't do any harm. Please explain the reasoning why is B wrong...........

Since both the civilizations existed at the same time there is no need of using past perfect tense here.

GMAT prefers to use simple tenses wherever possible.

[Chaitanya_1986]

Simple logic: When 2 actions occurring at same time then no need of past perfect.....

Use past perfect when 2 actions in past and u want to tell which happened before what then we will use the past perfect.