When Considering Demand and Supply in a Market Economy,it Is

When considering demand and supply in a market economy,it is correct to say that

A) demand refers to the price that consumers are willing to pay for a product.
B) the demand and supply schedule indicates how many units of a given product will be sold at different prices.
C) demand and supply curves are used to determine the demand and supply schedule.
D) equilibrium prices are only rarely achieved.
E) if a seller tried to increase profits by making more products to sell,the result would be a more efficient use of resources because economies of scale would be achieved.