With regard to the comparison between activity-based costing and traditional full cost calculation, of the following statements, the correct one is ().

Activity-based costing only allocates activity-based costs, not just variable costs. Option a is wrong. Activity-based costing uses a variety of cost drivers at different levels to allocate costs. All costs such as materials and labor that can be easily traced back to products can be directly attributed to specific products to minimize inaccurate distribution, so the scope of direct costs is larger than traditional cost calculation, and option C is wrong; The traditional full cost calculation method is to collect indirect expenses by department, while activity-based costing method is to collect indirect expenses, while the implementation of responsibility accounting and performance evaluation is aimed at departments. Therefore, compared with the traditional full cost calculation method, activity-based costing is not convenient to implement responsibility accounting and performance evaluation, that is, option BD is correct.