During 2021, it cost Swifty Inc. $11 per unit to produce Part T5. During 2022, the cost has increased to $15 per unit. In 2022, Cullumber Company has offered to sell the Part T5 for $9 per unit to Swifty. With regard to the make-or-buy decision, which statement is true? O Incremental costs are $2 per unit. Net relevant costs are $2 per unit. O Differential costs are $6 per unit. O Incremental revenues are $4 per unit