Comprehensive and Detailed In-Depth Explanation:
In SAP EWM, a delivery type (e.g., inbound or outbound) is defined by a document type, which is linked to a document category (e.g., "F" for inbound delivery). Option A ("A new document type and combine it with an existing document category") is correct because you create a new document type in SPRO: SCM Extended Warehouse Management > Cross-Process Settings > Delivery Processing > Document Types, and assign it to an existing category (e.g., "F" or "O"). Options B and C are incorrect because a process profile isn't required, and a new category isn't typically created. Option D is overly broad, as categories are predefined.