A manufacturing plant produces two types of widgets: standard model; deluxe model. Each unit requires the use of direct labor and labor time per unit differs between models. Manufacturing is done in production runs and each run has a set-up. For the month, the plant recorded the following: Standard Deluxe 2,000 1,000 Units produced $20.000 $30,000 Direct labor costs 4 12 Number of production runs Consider the salaries of production supervisors ($90,000). How much of this cost should be assigned to the standard units? Select one: O a. 22,500 O b. 30,000 O c. 36,000 O d. 45,000 O e. 60,000 O f. 67,500