​A market maker faces the following demand and supply for widgets.Eleven buyers are willing to buy at the following prices: $15,$14,$13,$12,$11,$10,$9,$8,$7,$6,$5.Eleven sellers are also willing to sell at the same prices.If the market maker makes three transactions,what is his total profit?

A) ​$12
B) $15
C) $18
D) ​$21

Total Profit

The total income of a business after all expenses and costs have been subtracted from its total revenues.

Market Maker

An entity that buys and sells large quantities of a particular asset to facilitate liquidity and efficiency in financial markets.

Transactions

are the actions or processes of buying, selling, or exchanging goods, services, or financial assets between two or more parties.