Question: What happens when the Mobile Terminal (MT) announces a network registration status of 'registered' or 'attached to 5GS' while VAE layer support is active, in the context of Vehicle-to-Everything (V2X) service identifier registration?
Option 1: The Terminal Equipment (TE) automatically initiates a new VAE layer registration using `+CVAEREG`.
Option 2: The TE ignores the network registration status update and continues with ongoing operations.
Option 3: The TE attempts to deactivate the VAE layer support but only after a predefined timeout.
Option 4: The TE deactivates the VAE layer support immediately using `+CVAEACT`.
Explanation: According to the described behavior for handling network registration status updates, when the MT announces that it is 'registered' or 'attached to 5GS', the TE is required to deactivate the VAE layer support if it is currently active. This deactivation is specifically done using the `+CVAEACT` command, ensuring seamless integration with the network's current state.