The symptoms of the participants in a recent decongestant effectivenes

The symptoms of the participants in a recent decongestant effectiveness study, including a required "stuffy nose," parallel that of the multitudes of Americans with the common cold each winter.
(A) parallel that of the multitudes of Americans with - THOSE should be used instead of THAT. Moreover, the word AFFLICTED should be present before WITH. Hence Incorrect.
(B) parallel those of the multitudes of Americans afflicted with - CORRECT
(C) parallel the multitudes of Americans afflicted with - This option changes the original intent. How could SYMPTOM be compared with Humans?? Hence Incorrect.
(D) parallels those of the multitudes of Americans afflicted from - Plural verb should be used instead of singular. Moreover, correct idiomatic expression is AFFLICTED WITH. Hence Incorrect.
(E) parallels that of the multitudes of Americans afflicted from - THOSE should be used instead of THAT. - Plural verb should be used instead of singular. Moreover, correct idiomatic expression is AFFLICTED WITH. Hence Incorrect.

KAPLAN OFFICIAL EXPLANATION:

The pronoun under investigation here is that and it refers, if you looked carefully, to symptoms in the first part of the sentence. Basically, using a pronoun instead of repeating symptoms allows the sentence to be a bit more concise, but the gesture fails in this sentence because that is the wrong pronoun. Since symptoms is plural, it needs a plural pronoun and that needs to be those. Eliminate (A) and (E). (C) eliminates the pronoun altogether, not a valid option if we want to maintain parallelism so take (C) out of consideration. (B) and (D) give you different verb options, but since, as we've noted, symptoms is plural, it takes a plural verb and (B) wins.

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