Since the 1940's the farms and ranches of the Great Plains

Question

10. Since the 1940's the farms and ranches of the Great Plains have been supplied with water from the Ogallala aquifer; this underground reservoir contained an estimated quadrillion gallons of water,  which equal Lake Huron,  but now reserves are becoming depleted.

(A) which equal Lake Huron
(B) which equal Lake Huron's
(C) equal to Lake Huron's
(D) the equivalent of Lake Huron's
(E) the equivalent of Lake Huron

gmatmba · Answer

It has to be D - the use of equivalent is necessary and  of Lake Huron's  is needed for parallel comparasions. We cannot use equal here as we are not sure if the content of water is exactly the same.

jjhko · Answer

It's not just a straight comparison between Ogallala aquifer and Lake Huron. It's the comparison of the volume of water"...an estimated quadrillion gallons of water" that needs to be compared to the 'volume' of Lake Huron (i.e. hence the possessive tense of 'Lake Huron's')

So I think it's down to B or D. I have a feeling that it should be D with the 'equivalent of' and not 'equal to'. 

But can someone better articulate why it should be D and not B?

Thx.

jjhko

yogi_d22 · Answer

"Equal" is generally used to comapare unaccountable quantities. 
For e.g. "Equal freedom".

So equivalent is or best choice.


Yogi

jaynayak · Answer

Indeed the choice is between C and D. Initially thought of C. But reading it thrice - D sounds good.

Since the 1940's the farms and ranches of the Great Plains

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