Avg - Avg price of cars
Total - Total price of cars
Num - Number of cars sold
Y1 - Past year
Y2 - Curr year

Avg Y2 > Avg Y1 ==> Total Y2/Num Y2 > Total Y1 /Num Y1
Now Num Y2 < Num Y1...So for the above inequality to be true Total Y2 > Total Y1. Now if the Total Y2 has to be gr8ter with number of cars dropped then the price of cars have to be greater than prev yr's or the same....Only C correctly mentions this...

Now if the above method doesnt strike u then use POE and eliminate the rest

A) nothing mentioned abt used cars - OUT OF SCOPE
B) tax reduction yet to come but the avg price has already risen, so cant be possible reason......ELIMINATE
D) a reason predicted to happen by end of yr...wht can this have an influence on price inc.....ELIMINATE
E) we're talking abt cars...not all vehicles, so why bring trucks and vans??? ......... OUT OF SCOPE

thanks a ton!!