Comprehensive and Detailed In-Depth Explanation:
The availability group in SAP EWM defines how stock is grouped for availability checks and is critical for inventory management integration with SAP S/4HANA. It is determined by the plant, storage location, and warehouse number. Option A ("Storage location") is correct because it specifies the physical or logical location within a plant, influencing stock availability. Option D ("Plant") is correct as it's the organizational unit tying inventory to a specific facility. Option E ("Warehouse number") is correct because it links the availability group to a specific EWM-managed warehouse. Stock type role (B) and non-location-dependent stock type (C) influence stock categorization but are not directly used to define the availability group; they are subordinate to the plant/storage location/warehouse structure. This configuration is maintained in SPRO: SCM Extended Warehouse Management > Goods Receipt Process > Configure Availability Group.