Refer to the Diagram, Which Relates to Firm A

Multiple Choice

Refer to the diagram, which relates to Firm A. Which of the following would shift A's average total cost curve from ATC ₁ to ATC ₂?

A) an increase in the price of a key component used by A in producing its product
B) a decrease in the incomes of A's customers
C) a move along A's total product curve (not shown)
D) an improved production method that shifts A's total product curve upward