Consumer Surplus: Buyer's Benefit from Market Price

Steps:

• Recall that consumer surplus is the difference between what consumers are willing to pay and what they actually pay.
• Evaluate each option against this definition to identify the match.
• Eliminate options describing producer benefits or costs unrelated to buyer gains.
• Confirm the option capturing the net gain for consumers.

Why D is correct:

• Consumer surplus is defined as the total benefit consumers receive when they pay less than their maximum willingness to pay, calculated as the area between the demand curve and the market price.

Why the others are wrong:

• A describes producer surplus, not consumer benefit.
• B refers to a cost of inaction, not the gain from buying.
• C states the willingness to pay for one consumer, not the overall surplus from lower prices.

Final answer: D