A manufacturer planned to produce and sell 1,000 units for the year. The budget contribution margin was $20 per unit and budget fixed costs were $5,000. Actual sales for the year were 800 units. Actual contribution margin was $18 per unit and actual fixed costs were $4,500. Calculate the sales volume variance for operating income. Select one: O a. 1,100 O b. 2,000 c. 3,600 d. 4,000 e. 5,100 O f. none of the above