Critical Reasoning

The World Automobile Association (WAA)
publishes a list of the "Best and Worst Drivers of
the World," ranking the drivers of every nation
according to the number of traffic deaths per
mile driven in that country.
Each of the following, if true, would by itself
provide a logical objection to using the WAA's
ranking as a representation of the quality of
drivers in each nation EXCEPT:
(A) The roads in some countries are in bad
repair and are therefore more dangerous
than roads in other countries.
(B) The average driver in industrialized
countries can afford to maintain his or her
car in better condition than can the
average driver in less developed countries.
(C) Some countries contain hundreds of
thousands of miles of road while other
countries contain relatively few miles of
road.
(D) Minor accidents that would cause little
injury in many countries are often fatal
when they occur in extremely mountainous
countries.
(E) Because of differences in national
economies, the average car in some
countries contains many more passengers
than does the average car in other
countries.
[spoiler]why is it not B instead of C?[/spoiler]