Which of the following is true? a. the supply-and-demand model always applies in service markets, but only sometimes applies in goods markets. b. the supply-and-demand model is appropriate for analysis under certain conditions. c. the supply-and-demand model is always appropriate for analysis. d. the supply-and-demand model always applies in goods markets, but only sometimes applies in service market

 (B.) The​ supply-and-demand model is appropriate for analysis under certain conditions.

Explanation:

Supply and Demand is an economic model that determines the price in market. It posit that, holding everything else constant, in competitive market, the price for a particular commodity, or other traded commodity such as labor, will change until it settles at a point where the quantity demanded will be to equal the quantity supplied, resulting in an economic equilibrium.