332. His studies of ice-polished rocks in his Alpine homeland, far outside the range of present-day glaciers, led Louis Agassiz in 1837 to propose the concept of an age in which great ice sheets had existed in now currently temperate areas.

(A) in which great ice sheets had existed in now currently temperate areas
(B) in which great ice sheets existed in what are now temperate areas
(C) when great ice sheets existed where there were areas now temperate
(D) when great ice sheets had existed in current temperate areas
(E) when great ice sheets existed in areas now that are temperate

OG-12-Q-70

Solution:

Tense*

A and D can be eliminated for the use of ‘had’ (had/past perfect tense is used to express that an action happened before another action in past; here, there is only one action in past).
C is awkward and wordy in “where there were areas now”.
E is awkward in “in areas now that are”.
B is the best choice.
Alternately,
‘When’ is used for a specific point in time and ‘in which’ is suitable for pointing a ‘time frame’. Thus, C, D, and E can be eliminated.
A uses ‘had’ incorrectly and thus, can be eliminated.
Thus, B is the best choice.

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