The European Union announced that cod and mackerel are the

KAPLAN OFFICIAL EXPLANATION

Attention to the Right Detail and Pattern Recognition are both essential to success on
Sentence Correction questions. You want to check the sentence very carefully for errors,
giving special consideration to the recurring patterns that the GMAT testmaker is so
fond of. In this sentence, there are two underlined pronouns plus an underlined verb.
Both underlined pronouns, “their” and “they,” refer to the European Union, which is
a singular noun. These pronouns are therefore incorrect; the sentence should use “its”
and “it,” respectively. Only (C) and (D) get both pronouns right, so one of these choices
has to be the correct answer. The difference between (C) and (D) is the use of “exceeds”
versus “exceed.” Since there are two kinds of fish, “cod and mackerel,” you need the
plural verb. Choice (D) is correct.