Which statement about the Cisco Webex hybrid service is true?

An employee has recently left an organization and a manager suspects that this employee may have made changes to the system that no one is aware of. Mobile and Remote Access registration is not working. Internal communications appear to be working, but no external system is able to register or call anywhere. While investigating this problem, it is discovered that no internal systems are able to call externally either. What is the TraversalZone missing that is causing this issue?

A company has enabled ICE to optimize call flows and improve video quality between their Cisco Collaboration endpoints internally and externally.
For which reason would you see activity on the TURN server when a call is established between two external endpoints?

A company is installing Cisco Collaboration infrastructure and one of the requirements is that they must be able to communicate with many external parties that are using H.323 and SIP. Internally they want to register the endpoints only on SIP.
Which functionality would describe the feature that needs to be enabled and where to achieve this?

When a Cisco Webex Video Mesh Node is configured for an organization, which process does the Webex Teams client use to discover the optimal bridging resource?