Which of the following statements is false? (You may select more than one answer.)

a. Activity-based costing systems usually shift costs from low-volume products to high-volume products.

b. Benchmarking can be used to identify activities with the greatest potential for improvement.

c. Activity-based costing is most valuable to companies that manufacture products that are similar in terms of their volume of production, batch size, and complexity.

d. Activity-based costing systems are based on the assumption that the costs included in each activity cost pool are strictly proportional to the cost pools activity measure.