Recall the Application About the Shutdown Price for Zinc to Answer

Recall the Application about the shutdown price for zinc to answer the following question(s) .
-Recall the Application. If the cost of mining zinc varies from one mine to another, the shutdown price for mining zinc

A) can also vary for each mine.
B) must remain uniform for all zinc mines.
C) will only vary in the long run.
D) cannot exist without uniform costs.