A work order has been created to perform corrective maintenance on a defective generator. All required information has been provided in the work order， but required materials are not in stock and have to be ordered. What is the status of the work order， after a maintenance manager has approved the work order？ （）
- A Approved （APPR）
- B Waiting on Materials （WMATL）
- C Waiting to be Scheduled （WSCH）
- D Waiting on Plant Condition （WPCOND）