Initial price of car = $x
After one year the price of car = $0.88x
to find the change in price we subtract the price after one year from initial price.
It means change in price = (x-0.88x)= 0.12x
By this we can easily see that , price dropped by 0.12
Or we can say that price dropped by 12%
So option C is the correct answer
C) 12% decrease