Consumers Choose ________. Consumers Are Efficient on the Market Demand Curve Because ________

Consumers choose ________.
Consumers are efficient on the market demand curve because ________.

A) to maximize profit;they only purchase goods and services that they can afford
B) to buy a good or service only if they will receive a consumer surplus;every point on the market demand curve maximizes consumer surplus
C) to purchase goods and services made with the newest technology;the market demand curve traces out the same path as the marginal revenue curve
D) to allocate their budgets to get the most value possible out of them;we derive a consumer's demand curve by finding how the best budget allocation changes as the price of a good changes
E) to allocate their budgets to get the most value possible out of them;they only purchase goods and services that they can afford