According to Marshall's definition, consumer surplus refers to the net income obtained by consumers through commodity exchange. Specifically, it is the difference between the consumer's willingness to purchase a product and the actual transaction price. This means that the size of consumer surplus It depends on two factors: the buyer's willing price and the actual transaction price. We know that the actual transaction price is the market price. No single buyer or seller can control the market price. It depends on the market. If the transaction price is the market price, the consumer's remaining size It depends on the buyer's willing price. The higher the buyer's willing price, the greater the consumer surplus. One item that matches the meaning of this text is:. ['Consumer surplus is affected by seller pricing behavior.', 'Consumer surplus will increase or decrease according to changes in market prices.', "The size of the consumer surplus depends on the buyer's willing price.", 'The size of consumer surplus is less affected by market changes.']