Use A for this item. When the destination MAC address is known, the switch forwards the frame only out the associated port. The MAC address table maps the destination MAC to the correct egress interface inside the VLAN. In Cisco CCNA 200-301 v1.1, Network Access questions frequently test the practical boundary between similar features: what the feature does, where it is configured, and what problem it is meant to solve. Flooding is used for unknown unicast, broadcast, or certain multicast traffic, not for a known destination MAC address. A clean way to validate the answer is to map the wording of the scenario to the actual device function. If the feature supplies addressing, forwarding, authentication, trunking, route selection, or controller communication, the answer must match that function exactly rather than a nearby protocol name.