Last year, both groups of scientists found that the glaciers in western Greenland had retreated far enough to set off

[BTGmoderatorDC]

Last year, both groups of scientists found that the glaciers in western Greenland had retreated far enough to set off an inherent instability in the ice sheet, one that experts have feared for decades.

(A) had retreated far enough to set off an inherent instability in the ice sheet, one that experts have feared for decades

(B) had retreated so far that it set off an inherent instability in the ice sheet, and it is one that experts for decades have feared

(C) had retreated so far that they set off an inherent instability in the ice sheet, one that experts for decades has feared

(D) have retreated far enough to set off an inherent instability in the ice sheet, one that experts feared for decades

(E) have retreated so far that they set off an inherent instability in the ice sheet, one feared by experts for decades


OA A

Source: Veritas Prep

[zs2]

(A) had retreated far enough to set off an inherent instability in the ice sheet, one that experts have feared for decades - CORRECT

(B) had retreated so far that it set off an inherent instability in the ice sheet, and it is one that experts for decades have feared

(C) had retreated so far that they set off an inherent instability in the ice sheet, one that experts for decades has feared

(D) have retreated far enough to set off an inherent instability in the ice sheet, one that experts feared for decades

(E) have retreated so far that they set off an inherent instability in the ice sheet, one feared by experts for decades

Hence A is correct.