Explain how are the slope of a production possibilities frontier and the opportunity cost of the goods related? A. The slope is a graphical representation of the cost of expanding production of both goods. B. The slope is a graphical measure of the growth rate of the economy. C. The slope is a graphical representation of the cost of decreasing unemployment. D. The slope is a graphical representation of the rate of trade-off between the goods. E. The slope is a graphical representation of the cost of economic growth in the economy.