An argument concludes that a city's residents strongly prefer public transportation over private cars, based on a survey conducted only among commuters arriving at the central bus station. What is the most significant flaw in this evidence?

The correct answer to the question "An argument concludes that a city's residents strongly prefer public transportation over private cars, based on a survey conducted only among commuters arriving at the central bus station. What is the most significant flaw in this evidence?" is Option C: The survey participants are a self-selected group, likely already favoring public transport..

The other options — A) The sample size of the survey was likely too small to be representative., B) The survey questions might have been leading or biased., D) The survey did not offer incentives for participation. — are incorrect for this GRE Exam Prep question. As explained above: This scenario represents sampling bias. Surveying only bus commuters skews the results, as this group is already predisposed to using public transportation, thus not representing all city residents.