The correct answer is B.
OBJ-3.2: VLAN hopping is the act of illegally moving from one VLAN to another. A VLAN (virtual LAN) is a logical grouping of switch ports extending across any number of switches on an Ethernet network. One of the most common VLAN hopping methods is to overflow the MAC table on a vulnerable switch. When this occurs, the switch defaults to operating as a hub and repeats all frames being received through all of its ports. This “fail open” method ensures the network can continue to operate, but it is a security risk that can be exploited by the penetration tester.