Which of the following statements about cost allocation is incorrect? a. A cost can be a direct or indirect cost, depending on the cost object of interest. b. A cost may be considered an indirect cost even if it has a one-on-one relation to the cost object, because the benefit of tracing this cost is too small. c. To ensure fairness, the same cost driver should be used to allocate costs for all indirect cost pools. d. The step-down method does not fully recognise the mutual dependencies between support departments e. A training program offered by the human resources department can be a cost object