J&J Materials and Construction Corporation produces fertilizer and distributes the product by using dump trucks. The company uses budgeted fleet hours to allocate variable manufacturing overhead. The following information pertains to the company's manufacturing overhead data: Budgeted output units Budgeted machine-hours Budgeted variable manufacturing overhead costs for 680 loads$72,590 680 truckloads 476 hours Actual output units produced Actual machine-hours used Actual variable manufacturing overhead costs 615 truckloads 376 hours $67,790 What is the flexible-budget variance for variable manufacturing overhead? A. $4,800 unfavorable OB. S4.800 favorable C. $2,139 unfavorable D. $2.139 favorable