Comprehensive and Detailed In-Depth Explanation:

A delivery document in EWM is defined by its document type and category. Option A ("Document type") is correct as it specifies the delivery’s purpose (e.g., "INB" for inbound), configured in SPRO: SCM Extended Warehouse Management > Delivery Processing > Document Types. Option D ("Document category") is correct because it classifies the document (e.g., "F" for inbound, "O" for outbound), linking it to ERP. Item category (B) and item type (C) are relevant for items within the delivery, not the document header definition.