Jammers are non-Wi-Fi interferers that can be identified by Metageek Chanalyzer. They intentionally disrupt wireless communications by emitting radio frequencies that interfere with Wi-Fi signals. Chanalyzer is designed to detect such patterns of interference.
https://www.metageek.com/training/resources/wifi-and-non-wifi-interference

When designing anchor redundancy for guest clients with auto-anchor configured on a WLC running version 8.1 or above, setting up Guest Anchor Priority ensures that one anchor is treated as active while another acts as standby rather than load-balancing clients between anchors which is not desired in this case. Reference := (CCNP Enterprise Wireless Design ENWLSD 300-425 and Implementation ENWLSI 300-430 Official Cert Guide Premium Edition and Practice)

When designing a wireless network for diverse clients, it's crucial to ensure that the network will be reliable for all users. Therefore, surveys should be conducted with the client that has the worst RF characteristics, as indicated in option D. This approach ensures that the network is designed to support even the weakest client, thereby providing a consistent experience for all users.
https://documentation.meraki.com/MR/WiFi_Basics_and_Best_Practices/Conducting_Site_Surveys_with_MR_Access_Points

In Cisco WLC release 8.9, the controller software can scale up to 20 WLCs and 3000 APs within a single RF group. This capability allows the Radio Resource Management (RRM) algorithms to function effectively across a larger network, optimizing the wireless experience by managing the RF environment and resources across multiple controllers and access points.