Assume That a Purely Competitive Firm Sold 100 Units of Output

Assume that a purely competitive firm sold 100 units of output today and the marginal revenue from the 100th unit sold was $4.00. If instead of 100 units it sold 1,000 units, the marginal revenue from the 1,000th unit would have been:

A) $4.00.
B) less than $4.00.
C) more than $4.00.
D) less or more than $4.00, depending on where its buyer was located.