Which of the following is a prerequisite for assigning a warehouse order to a resource...

Comprehensive and Detailed In-Depth Explanation:

Automatic assignment of warehouse orders to resources in SAP EWM requires queue linkage. Option C ("The warehouse order must be in a queue that is assigned to the resource either directly or through a resource group") is correct, as queues connect orders to resources, configured in SPRO: SCM Extended Warehouse Management > Resource Management > Assign Queues. Option B is a supporting factor but not the prerequisite, while options A and D are not mandatory conditions.