GMAT Critical Reasoning (CR) | Re: The heavy traffic in Masana is a growing drain on the city's economy

A is a trap because we will not know if this fact is helpful for the plan to remove the problem.
C is right even though it has "in other urbans", the main idea in C is that the plan will encourage people to use carpool; thus, the plan will succeed. "in other urbans" is just an evidence to support the idea that carpool will work.

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