Requirement 5. CC's managers are wondering if they should further refine the department-by-department costing system into an ABC system by identifying different activities within each department. Under what conditions would it not be worthwhile to further refine the department costing system into an ABC system? O A. If there wasn't much variation among contracts in the consumption of activities within a department. O B. If a single activity accounts for a sizable proportion of the department's costs. O C. If significant costs are incurred on different activities within a department, but each activity has the same cost driver. O D. All of the above