Essentials of Economics 7th Edition by Gregory Mankiw

Exercise 11

A firm is producing 1,000 units at a total cost of $5,000. If it were to increase production to 1,001 units, its total cost would rise to $5,008. What does this information tell you about the firm?
A) Marginal cost is $5, and average variable cost is $8.
B) Marginal cost is $8, and average variable cost is $5.
C) Marginal cost is $5, and average total cost is $8.
D) Marginal cost is $8, and average total cost is $5.