GMAT Critical Reasoning (CR) | Re: Margaret: According to a report provided by the National Emp

this is a common pattern in gmat, and kaplan has one question similar to this question in the book.
yes, C is correct.
Ones can understand the argument in this way. There are around 20% of security guards used to be police officers. Of the rest, lower than 20% of security guards will come from any Lithian.

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