For similar cars and drivers, automobile insurance for

For similar cars and drivers, automobile insurance for collision damage has
always cost more in Greatport than in Faimont. Police studies, however,
show that cars owned by Greatport residents are, on average, slightly less
likely to be involved in a collision than cars in Fairmont. Clearly, therefore,
insurance companies are making a greater profit on collision-damage
insurance in Greatport than in Fairmont.

Which of the following is an assumption on which the argument depends?

A. Repairing typical collision damage does not cost more in Greatport
than in Fairmont.
B. There are no more motorists in Greatport than in Fairmont.
C. Greatport residents who have been in a collision are more likely to
report it to their insurance company than Fairmont residents are.
D. Fairmont and Greatport are the cities with the highest collisiondamage
insurance rates.
E. The insurance companies were already aware of the difference in the
like lihood of collisions before the publication of the police reports.