If Mario's Pizza offers consumers who purchase one medium sized pizza a second pizza at half price, this is an example of ________.

Refer to the above figure. At the initial long-run equilibrium, the price level is ________, and the price level will be ________

A) 20; 40 B) 20; 45 C) 40; 45 D) 20; 20

Many less developed countries have low rates of economic growth because

a. high population growth rates reduce living standards b. low population growth rates result in an inadequate labor supply c. high current output per capita reduces incentives for growth d. interest rates are too high e. they invest too much in infrastructure leaving little for private capital investment