A Friend of Yours Asks You Why Market Prices Are

A friend of yours asks you why market prices are better than government-determined prices. What do you say?

A) because they generally reflect the value of a good to society, but not the cost of making it
B) because they generally reflect the cost of making a good to society, but not its value
C) because they generally reflect both the value of a good to society and the cost of making it
D) because they generally reflect neither the value of a good to society nor the cost of making it