Stryker Industries received an offer from an exporter for 29,000 units of product at $18 per unit. The acceptance of the offer will not affect normal production or domestic sales prices The following data are available: Domestic unit sales price Unit manufacturing costs: Variable Fixed $22 10 3 The differential cost from the acceptance of the offer is Oa $638,000 Ob. $290,000 Oc 5522,000 Od. 587,000