Which of the following statements is true with regard to activity-based costing rates? Select one: O a. All cost drivers used to determine the rates will be unit-level drivers. O b. ABC is simpler and less expensive to implement than other traditional methods of allocating overhead costs. O c. none of the given answer. O d. ABC is another way to refer to a multiple departmental rate situation. Oe. The premise of ABC is that activities are what cause costs to be incurred.