Refer to the graph below. The slope of the line tangent to the curve at point A is:

In recent decades, international trade has been

a. a constant percentage of U.S. GDP b. a declining fraction of U.S. GDP c. an increasing fraction of U.S. GDP d. declining as measured by total dollars spent e. constant as measured by total dollars spent

Which of the following is most likely to cause the productivity of labor to increase?

a. higher money wages b. a higher rate of investment in human and nonhuman capital c. more flexible working hours and improved retirement plans d. an increase in the proportion of the workforce that belongs to a labor union