Sarah is trying to decide whether she should continue to operate her division or shut down her division. What type of decision does she face? Select one a Product mix decision O b. Accept or reject a special order c. Keep or drop decision d. Make or buy decision Irrelevant costs can be defined as: Select one: O a. costs that will change as circumstances change. b. costs that are not determinable. O C. costs that will stay the same regardless of which decision is made.. O d. costs that will change as revenues change W