Which of the following mathematical expressions represents the equation of a straight line with a slope of zero at all points on a graph with Y on the vertical axis and X on the horizontal axis?

The figure above shows the costs and benefits associated with producing paper. What is the efficient level of output?

A) 0 B) 4 tons C) 6 tons D) More than 6 tons E) None of the above answers is correct.

Because the productivity of labor decreases as the quantity of labor employed increases

A) the quantity of labor a firm demands increases as the real wage rate decreases. B) the quantity of labor a firm demands increases as the money wage rate decreases. C) the labor demand curve shifts right as the real wage rate decreases. D) the aggregate production function shifts upward as the real wage rate decreases.