Question: During a handover from CDMA2000 Access to E-UTRAN, how does the MME initiate lawful interception based on subscriber identity?
Option 1: By monitoring detach events from the E-UTRAN
Option 2: Through periodic location updates from the UE: User Equipment
Option 3: Based on the S-GW: Serving Gateway and PDN-GW: Packet Data Network Gateway interface protocols alone
Option 4: By intercepting the attach event received from the HRPD AN (Access Network) based on IMSI: International Mobile Subscriber Identity
Explanation: This is correct because, during handovers between different access technologies, the MME uses the attach event triggered by the handover to initiate interception. This attach event, identified by the subscriber's IMSI, ensures targeted interception across heterogeneous networks.