The market demand curve A. cannot show how quantity demanded changes in response to a change in price. B. is the vertical sum of individual demand curves. C. cannot show a change in demand for a good. D. is upward sloping. E. is the horizontal sum of individual demand curves.

Which of the following results in an increase in the standard of living? a. an increase in unemployment pushes down the cost of production. b. wages go up to correct for the inflation of prices. c. income increases, enabling consumers to buy more goods and services. d. rising production costs drive up the price of goods and services.