GMAT Sentence Correction (SC) | Despite a growing population, in 1998 the United States used 38

Despite a growing population, in 1998 the United States used 38 billion fewer gallons of water aday when comparing it to the period of all-time highest consumption almost 20 years earlier.

Issue:Comparison

Analysis: Looking at the underlined portion of the sentence, we can say that the water to consumption in US is being compared. Hence, we need to use the correct comparison marker and make sure that the compared things are equal.

A. daywhen comparing it to the period of all-time highest
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