The costs in time and other resources that parties incur in the process of facilitating an exchange of goods and services are called

The market supply curve for any product:

a. always depends on the market demand for that product. b. depends on the general income level of the consumers in the market. c. is a summation of individual firms' supply curves. d. equals the total revenue generated through sale of the commodity. e. is affected by the prices of related products.

Normal profit implies that

A. Economic profit must be negative. B. Firms will expand their scale of production. C. The factors employed are earning as much as they could in the best alternative employment. D. Economic profit must be positive.