A perfectly competitive firm currently sells 30,000 cartons of eggs at $0.50 each. If the firm wants to sell one more carton of eggs, the firm
a. Should raise its price above $0.50
b. Must sell the carton for less than $0.50
c. Should price the carton at $0.50
d. Cannot sell an additional carton at any price because there are other egg farmers in the market