Use the Following to Answer Questions

Multiple Choice

Use the following to answer questions:
-(Table: Lunch) Look at the figure Lunch. Joe makes and sells picnic lunches to people taking all-day rafting trips on the river. The marginal cost and average cost of each lunch are a constant $4. If Joe is one of many firms in a competitive industry, how many lunches will he produce in the long run?

A) 0
B) 20
C) 40
D) 60