During 2021, it cost Sunland Inc. $11 per unit to produce Part T5. During 2022, the cost has increased to $15 per unit. In 2022, Blossom Company has offered to sell the Part T5 for $9 per unit to Sunland. With regard to the make-or-buy decision, which statement is true?

Incremental costs are $2 per unit.

Incremental revenues are $4 per unit.

Differential costs are $6 per unit.

Net relevant costs are $2 per unit.