Which of the Following Is Correct

Multiple Choice

Which of the following is correct?

A) A firm's long- run average cost curve is derived from a series of short- run average cost curves.
B) A firm's long- run total cost is the difference between its long- run fixed cost and long- run variable cost.
C) A firm's short- run average cost curve is derived from a series of long- run average cost curves.
D) Both answers A and C are correct.