Answer A is the technically correct selection. CDP is disabled on a specific interface with the interface-level no cdp enable command. The requirement is to turn off CDP only on the port with the last usable address in the /30 subnet, so the correct interface must be selected and CDP disabled there. This aligns with Cisco CCNA 200-301 v1.1 because the exam blueprint requires engineers to recognize operational behaviour from configuration symptoms and topology requirements. clear cdp table only clears learned neighbors, advertise- v2 changes advertisement format, and no cdp run is a global command rather than an interface command in this context. Treat the distractors carefully: most are real Cisco terms, but they solve a different problem or operate at a different layer. The selected answer is the one that would be used by an engineer on the device or in the design to produce the outcome stated in the question.