Answer: Are willing and able to supply at different prices.
Explanation:
Market supply refers to the total supply of goods are services in the market. It can be summarized as the total amount of goods that all individual firms in the market are able and willing to supply at different prices.
The market supply curve can be found by the horizontal summation of the individual supply curves at different prices.
Thus, the correct option is all firms are willing and able to supply at different prices.
