GMAT Sentence Correction (SC) | Re: Bufo marinus toads, fierce predators that will eat frogs,

Correct choice must be A

Reasoning as follows :

Subject of the underlined portion is fierce predators (Plural) hence verb must be Plural .
Time line of event : Since it is informational statement, hence tense must be simple, therefore D & E are out,
as they uses past perfect tense.

now A/B/C : Difference is in between idiomatic usage of attemp :

A) : in an attempt to control (Sounds Good & Grammatically correct also)
B) Wrong attempts (Plural) wrong
C) In an attempt for controlling
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