Refer to the table above. What is the firm's marginal cost when it produces 55 units of the good?

In the short run, why does a production function eventually display diminishing returns to labor?

A) As a firm hires more workers the skills and the work ethic of the additional workers will eventually decline. B) The opportunity cost of hiring additional workers must eventually rise. C) As the number of workers increases eventually the gains from the division of labor and specialization are used up. D) As the number of workers increases it becomes difficult to monitor them.

Suppose a country is much richer than the others in the Solow growth model. What happens in the long run?

A) The other countries catch up to the rich one. B) The rich country grows the fastest. C) The rich country becomes poorer than the others. D) Nothing.