Question: In a Universal Subscriber Identity Module (USIM) application, when the Mobile Equipment (ME) needs to update the Accumulated Call Meter (ACM) value, which procedure does it perform on the Elementary File (EF) for ACM?
Option 1: Reading procedure with EFACM
Option 2: Updating procedure with EFACM using a new initial value
Option 3: Increasing procedure with EFACM sending the value to be added
Option 4: Deleting procedure with EFACM to reset the value
Explanation: When updating the Accumulated Call Meter (ACM) value in a USIM application, the Mobile Equipment (ME) needs to increment the existing value. This is achieved by performing an "Increasing procedure" on the Elementary File for ACM (EFACM), where the ME sends the specific value that needs to be added to the current ACM total. This ensures the ACM reflects the accurate accumulated usage. **Option 3** correctly identifies this process, distinguishing it from initial updates (Option 2), reading the current value (Option 1), or a non-applicable deletion procedure (Option 4).