We learn that the New Urbanists believe that suburban sprawl contributes to the decline of civic life and civility (lines 4 to 9). However, answer choice (A) is incorrect because it is too strong.
The New Urbanists believe that the increase in time required to get from one place to another can negatively impact civility and community life. What we do not learn whether they believe that this is the primary factor affecting the maintenance of civility. Rather, it is one of many factors of suburban sprawl that the New Urbanists suggest contributes to the decline of civility.
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