What is the difference between 1000BASE-LX/LH and 1000BASE-ZX interfaces?

1000BASE-LX/LH is supported on links up to 10km, and 1000BASE-ZX operates over links up to 70 km. The answer follows from normal Cisco device behavior and the operating clue in the scenario. Cisco CCNA 200-301 v1.1 includes this under Network Fundamentals, where the expected skill is identifying the mechanism that actually satisfies the scenario. The wording usually gives the decisive clue: a protocol number, a route prefix, a control-plane role, a wireless security method, or a management command. The other options use adjacent terms, wrong-layer behavior, or configuration that would not produce the requested result. In a real network, selecting the wrong option would usually produce a failed adjacency, broken client connectivity, insecure management access, or an incorrect forwarding path. The selected answer matches the Cisco behavior and configuration model required by the question, so it is retained as the verified answer for this item.