Dear Friends,
Here is a detailed explanation to this question-
manishkhare wrote:
Flocks of birds and schools of fish instinctively use highly-coordinated wavelike movement, a method to protect themselves against predators that would much rather attack an individual member that strays from the group.
A) a method to protect
B) as a method protecting
C) as a protection of
D) protecting
E) to protect
Meaning is crucial to solving this problem:Understanding the intended meaning is key to solving this question; the intended meaning of this sentence is that flocks of birds and schools of fish instinctively use highly-coordinated wavelike movement, and in doing so protect against predators that would much rather attack an individual member that strays from the group.
Concepts tested here: Meaning + Modifiers + Verb Forms• In the “noun + comma + phrase” construction, the phrase must correctly modify the noun; this is one of the most frequently tested concepts on GMAT sentence correction.
• The introduction of present participle (“verb+ing”- “protecting” in this case) after comma generally leads to a cause-effect relationship.
• The infinitive verb form ("to + base form of verb" – “to + protect” in this sentence) is the preferred construction for referring to the purpose or intent of an action.
A: Trap. This answer choice incorrectly modifies "wavelike movement" with "a method to protect", incorrectly implying that the wavelike movement is a method that the flocks of birds and schools of fish instinctively use to protect against certain predators; the intended meaning is that
by taking the action of
using the wavelike movement, flocks of birds and schools of fish protect themselves against certain predators; please remember, in a “noun + comma + phrase” construction, the phrase must correctly modify the noun.
B: This answer choice incorrectly modifies "wavelike movement" with "as a method protecting", incorrectly implying that the wavelike movement is a method that the flocks of birds and schools of fish instinctively use to protect against certain predators; the intended meaning is that
by taking the action of
using the wavelike movement, flocks of birds and schools of fish protect themselves against certain predators; please remember, in a “noun + comma + phrase” construction, the phrase must correctly modify the noun.
C: This answer choice incorrectly modifies "wavelike movement" with "as a protection of", illogically implying that the wavelike movement is a protection of the flocks of birds and schools of fish against certain predators; the intended meaning is that
by taking the action of
using the wavelike movement, flocks of birds and schools of fish protect themselves against certain predators; please remember, in a “noun + comma + phrase” construction, the phrase must correctly modify the noun.
D: Correct. This answer choice correctly modifies "wavelike movement" with "protecting themselves against predators...group"; the use of the "comma + present participle (“verb+ing”- “protecting” in this case)" conveys the intended meaning - that flocks of birds and schools of fish instinctively use highly-coordinated wavelike movement, and in doing so protect against certain predators; please remember, the introduction of the present participle (“verb+ing”- “protecting” in this case) after comma generally leads to a cause-effect relationship.
E: Trap. This answer choice alters the meaning of the sentence through the phrase “to protect”; the use of the infinitive verb form ("to + base form of the verb" – “to + protect” in this sentence) modifies the verb “use”, incorrectly implying that flocks of birds and schools of fish
purposefully use highly-coordinated wavelike movement
for the purpose of protecting themselves from certain predators; the intended meaning is that flocks of birds and schools of fish instinctively use highly-coordinated wavelike movement,
and in doing so protect against certain predators; please remember, the infinitive verb form ("to + base form of verb" – “to + protect” in this sentence) is the preferred construction for referring to the purpose or intent of an action.
Hence, D is the best answer choice.To understand the concept of "Comma + Present Participles for Cause-Effect Relationships" on GMAT, you may want to watch the following video (~3 minutes):
To understand the concept of "Phrase Comma Subject" and "Subject Comma Phrase" on GMAT, you may want to watch the following video (~1minute):
All the best!
Experts' Global Team
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