Use C for this item. Overlapping Wi-Fi channels cause contention and interference, which reduces wireless performance. Clients and APs sharing overlapping spectrum must wait, retransmit, or deal with corrupted frames. 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. Overlapping channels do not inherently change SSID visibility or create encryption exposure, but they do degrade throughput and reliability. 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.