Question: Upon sending an SGsAP-IMSI-DETACH-INDICATION message to the VLR for implicit IMSI detach from non-EPS services, what action does the MME take regarding the state of the SGs association and what timer is started?
Option 1: The MME moves the state to SGs-ACTIVE and starts timer Ts5.
Option 2: The MME keeps the current state unchanged and starts timer Ts15.
Option 3: The MME moves the state to SGs-NULL but does not start any timer.
Option 4: The MME moves the state of the SGs association to SGs-NULL and starts timer Ts10.
Explanation: After sending the SGsAP-IMSI-DETACH-INDICATION message, the MME updates the SGs association state to SGs-NULL and initiates timer Ts10 to track the response time from the VLR, awaiting an SGsAP-IMSI-DETACH-ACK message.