Volume Variable cost per unit Fixed costs 900 unts per month so per unt $13.000 per month wat not be able to use the eacess capacty in any prohtable mannec. If Wath decides to cubsource, morthy eperating income wall A ncrease by $13.000 B. decrease by $3,300 C. decrease by $13,000 D. harease by 57,200