Speedy Supplies sells a product at a price of $100.00. Its variable manufactured cost is $20.00 and the variable marketing cost per unit is $14.50 with fixed cost per period of $20,000. What would be the change in operating income under variable costs if sales increase from 8,000 to 8,100 units? OA $8,550 OB. Loss of $13,450 Oc. $6,000 OD. $6,550