sivatx2
This is a pronoun reference problem, it will try to associate to the closest noun, which in this case is the nickname. Hence you should avoid such ambiguity in GMAT answer choices.
In most of the questions you should do so, but in many questions, especially the hard ones, the logic is always best to rely on rather than grammatical rules.
GMAT not only tests the ability to identify the grammatical errors, but also tests the ability to comprehend the intended meaning.
If you think from the perspective of grammatical errors then the original statement is wrong (it refers to either the white tiger or the lightning). However, when you think logically, how can a nickname move quickly in the first place?
From what I have seen, Intended meaning > Grammatical issues. Although some ambiguity exists, if you come across such option do not mark it as incorrect. Instead, glance over other options, if other options do not convey the intended meaning then the original statement (white tiger.... quickly) will be the correct answer.
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