B it is.
It means that despite the total costs to the insurance co of insuring the "less driving" drivers is lower than the "more driving" drivers, they pay the same - thus in effect cross subsidizing the insurance of "more driving" drivers.
A is irrelevant - talks abt new buyers.
C is irrelevant - talks abt age of drivers
D is irrelevant - talks about higher costs to drivers (and thus higher profits to the insurance co) if insurance is made available on the basis of mileage. Does not talk about cross subsidy.
E is irrelevant too - talks about unequal insurance rates which have nothing to do with distances driven.
Who says elephants can't dance?