Question: In a 3GPP SAE security architecture, after an eNB decides to update the Security Key for Wireless Trust (S-KWT), what action is taken by both the UE and WT regarding the use of multiple S-KWT keys?
Option 1: The UE and WT discard all previous S-KWT keys immediately.
Option 2: The UE and WT continue using the oldest S-KWT key for subsequent WLAN authentications.
Option 3: The UE and WT start using the latest (freshly derived) S-KWT, with multiple keys present.
Option 4: The eNB selects which S-KWT key the UE and WT should use from among the multiple available.
Explanation: When there are multiple S-KWT keys at the UE and the WT, the latest derived S-KWT shall be used for subsequent WLAN authentications, ensuring the most recent security measures are applied, enhancing security by utilizing the freshest encryption context.