Use A for this item. The global spanning-tree portfast default command makes access ports transition to forwarding immediately when endpoints connect. PortFast is intended for host-facing access ports so DHCP and initial connectivity are not delayed by STP listening and learning behaviour. 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. The trunk PortFast command is for special trunk edge cases, and disabling PortFast would not meet the requirement. 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.