A, the first one only, this parabola only has a minimum and no maximum. the other statements are also just false
So the original price is "x".
the discounted price by 10% is P(x) = 0.9x.
the price minus a $150 coupon is C(x) = x - 150.
so, if you go to the store, the item is discounted by 10%, so you're really only getting out of your pocket 90% of that, or 0.9x, but!!! wait a minute!! you have a $150 coupon, and you can use that for the purchase, so you're really only getting out of your pocket 0.9x - 150, namely the discounted by 10% and then the saving from the coupon.
C( P(x) ) = P(x) - 150
C( P(x) ) = 0.9x - 150
