Question: Upon T304 expiry indicating handover to E-UTRA failure, what action(s) should a UE (User Equipment) take if the source Radio Access Technology (RAT) is **not** E-UTRA?
Option 1: Perform actions as specified for E-UTRA failure in the E-UTRA protocol specification.
Option 2: Reset MAC (Medium Access Control) and perform actions defined for this failure case specific to the source RAT.
Option 3: Ignore T304 expiry and continue with current RRC (Radio Resource Control) state.
Option 4: Initiate a new handover procedure to the original source cell.
Explanation: According to the protocol, if the source RAT is not E-UTRA upon T304 expiry (handover to E-UTRA failure), the UE must take two specific actions: 1. **Reset MAC**: This ensures a clean state for potential future handovers or communication attempts. 2. **Perform actions defined for this failure case as specified in the applicable RAT's specifications**: This allows handling of the failure in a manner tailored to the source RAT, ensuring compatibility and optimal recovery procedures across different technologies.