Question: When a Mobile Equipment (ME) needs to update its Local Service Area (LSA) information, which of the following Elementary Files (EFs) does it primarily use for the updating procedure?
Option 1: EFSLL (Local Service Location List)
Option 2: EFSAI (Service Area Identifier List)
Option 3: EFLOCIGPRS (GPRS Location Information)
Option 4: Both EFSAI and EFSLL
Explanation: According to the LSA information update procedure, the Mobile Equipment (ME) primarily performs the updating procedure with EFSLL. This is because EFSLL contains the list of local service areas relevant to the subscriber's current location or service needs, necessitating its update for LSA information changes.