18. In a job costing system, all of the following statements about materials are correct EXCEPT for which of the following? (1.5 Points) c. Materials that cannot be traced to a particular job are treated as manufacturing overhead. b. The job cost record for a job will contain all direct material used for that particular job. a. A materials requisition is used to request materials needed from the storeroom. d. All materials are always classified as direct materials.