The loading, unloading, transshipment and transit of inward and outward mail bags are （）Customs control and a covering way bill should be submitted to the Customs by the enterprise providing postal service.

A. A bond is needed when the bill of lading is unavailable when the goods arrive at the destination.
B. A bond is needed when the bill of lading arrives at the port of destination.
C. A bond is not needed when the goods arrive at the destination.
D. A bond is needed when the goods arrive at the destination if there is no bill of lading at all.