If the public library shared by the adjacent towns of Redville and Glenwood were relocated from the library's current...

I had understood the reasoning behind B and that was my first answer choice. But I had changed my answer to D because my thinking was that since the library in Redville is further away from Glenwood that people from Glenwood would drive there. With choice D since people driving would still drive I thought that even if the library was changed to Glenwood drivers from Glenwood would still drive and walkers won't increase as a result, therefore, weakening the argument. Can someone please explain the error in my thinking? Is it assuming the distance between Glenwood and Redville library and thinking Glenwood people will automatically be more drivers compared to Redville?