A receiving host computes the checksum on a frame and  determines that the frame is damaged.Theframe is then discarded.At which OSI layer did this happen？（）

A.added security
B.dedicated bandwidth
C.provides segmentation
D.allows switches to route traffic between subinterfaces
E.contains collisions

A.can be used over analog circuits
B.maps Layer 2 to Layer 3 address
C.encapsulates several routed protocols
D.supports IP only
E.provides error correction

A.one IP network or subnetwork for each subinterface
B.subinterface numbering that matches vlan tages
C.subinterface encapsulation identifiers that match vlan tags
D.a management domain for each subinterface
E.one physical interface for each subinterface
F.one subinterface per vlan