Use A for this item. PortFast lets an edge port move to forwarding immediately when a host is connected. It bypasses the traditional listening and learning delay for endpoint ports while still allowing STP protection features such as BPDU Guard. 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. BPDU Guard protects edge ports, while UplinkFast and BackboneFast are older convergence enhancements with different purposes. 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.