Stryker Industries received an offer from an exporter for 27,000 units of product at $18 per unit. The acceptance of the offer will not affect normal production or domestic sales prices. The following data is available: Domestic unit sales price $25 Unit manufacturing costs: Variable 13 Fixed What is the differential cost from the acceptance of the offer? a. $675,000 b. $135,000 c. $486,000 d. $351,000