A business analysis of the Appenian railroad system divided its long-distance passenger routes into two categories: rural routes and interurban routes. The analysis found that, unlike the interurban routes, few rural routes carried a high enough passenger volume to be profitable. Closing unprofitable rural routes, however, will not necessarily enhance the profitability of the whole system, since__. Which of the following most logically completes the passage?
A: not all of Appenia's large cities are equally well served by interurban railroad services
B: the rural routes were all originally constructed at least one hundred years ago, whereas some of the interurban routes were constructed recently for new high-speed express trains
C: a large part of the passenger volume on interurban routes is accounted for by passengers who begin or end their journeys on rural routes
D: the greatest passenger volume, relative to the routes' capacity, is not on either category of long-distance routes but is on suburban commuter routes
Choose A, B, C or D as your solution.
C