Football superstar quarterbacks in the NFL earn millions of dollars each year while school teachers may earn fifty thousand, which of the following help explain this phenomenon?

A. Consumers enjoy football to the point that they are willing to spend lots of money and time attending games and watching commercials.

B. Differences in supply - the supply of superstar players is very low, while the supply of competent teachers is much larger

C. Demand for superstar quarterbacks' talents is very high since they can generate so much revenue for a team and NFL

D. All of the above