OG10-80

IRENEYI

80. 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

flourishing at the same time as those were

The correct answer is A, would u pls help to analysis?

shanexwang

same as -->eliminate c missing as
civilization is better than those to avoid ambiguity ( i feel like "those" always followed by of sth.)
had flourished is not necessary. just use flourished.