Comprehensive and Detailed In-Depth Explanation:

Yard Management in SAP EWM tracks vehicle movements. Option A ("Doors") is correct as they connect the yard to the warehouse, and option B ("Vehicles") is correct as they are the objects managed, both configured in SPRO: SCM Extended Warehouse Management > Yard Management. Option C (resources) is warehouse-specific, and option D (checkpoints) is optional, not mandatory.