Anthony uses a standard costing system and allocates overhead costs to each unit of output using labour hours. Budgeted labour time is 4 hours per unit of output. The following is information for the month: Actual Results Static Budget Number of units produced 280 240 Hours of labour time 988 Variable overhead cost per hour $28 Mariable overhead cost $34,580 Fixed manufacturing overhead cost $19,800 $20,160 What is the production-volume variance? Select one: a. $360 favorable Cross out b. $1,680 favorable Cross out Cross out c. $840 favorable d. $0 cross out