A Cisco engineer must configure a single switch interface to meet these requirements• accept untagged...

Option C. Switching behavior depends on VLAN tagging, trunk negotiation, STP role selection, EtherChannel mode, and whether a protocol is standards-based or Cisco-specific. Cisco CCNA 200-301 v1.1 includes this under Network Access, where the exam expects engineers to recognize the device behavior that actually produces the required outcome. The question is best solved by reading the operational clue rather than choosing a familiar acronym. Incorrect options change existing VLAN reachability, use the wrong negotiation behavior, or apply a feature to the wrong switch function. In a production network, the wrong choice would normally create an outage, leave a management or security gap, or send troubleshooting toward the wrong subsystem. The selected answer is the one that matches the control-plane, data-plane, wireless, security, services, or automation mechanism described in the question. That is why it remains the verified answer for this item.