Rent seeking refers to the asking prices for goods and services being sold on the black market

An individual purchasing goods and services will allocate his expenditures so that the pleasure he gets out of spending one more dollar is the same no matter what he spends that dollar on. For a firm purchasing resources, this is the same as ensuring that:

a. the ratio between marginal revenue product and the marginal factor cost is equal for all the resources used. b. the marginal revenue product of the resources are equal. c. the marginal factor cost of the resources are equal. d. the ratio between marginal revenue product and the marginal factor cost is greater than one for all resources. e. the marginal revenue product is greater than the marginal factor cost of all resources.

How do we measure the slope of a linear curve?