A change in which of the following will change the optimal rate of output?

The U.S. economy has had persistent inflation in recent decades. A possible explanation for the inflation is that

A) there have been decreases in the growth rate while aggregate demand has remained unchanged. B) growth in aggregate demand has been greater than growth in aggregate supply. C) there have been decreases in aggregate demand while aggregate supply has remained unchanged. D) there have been increases in the growth rate while aggregate demand has remained unchanged.

Refer to Figure 18.3. The opportunity cost of producing scooters in Livonia is

A) 2/3 of a pogo stick. B) 6/5 of a pogo stick. C) 1.5 pogo sticks. D) 1.25 pogo sticks.