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 wants to make three transactions, what should he bid (the suppliers)
a. 9
b. 8
c. 7
d. 6
a. 9
b. 8
c. 7
d. 6