Under which circumstance will a switch drop a frame?

A. If the destination MAC address of the frame is unknown in the MAC address table
B. If the source MAC address of the frame is unknown in the MAC address table
C. If the frame is deemed to be corrupt via the CRC
D. If the destination MAC address exists in another switch’s MAC address table

C. The only time a frame is dropped is when the cyclic redundancy check (CRC) calculated against the frame’s payload deems the frame corrupt. If the destination MAC address is not known, it will be flooded to all active ports on the switch, but it will not be dropped.