Question: What is the implication for the presence of EFBDN on the EFCMI (Comparison Method Information) Elementary File in a SIM-ME interface?
Option 1: EFCMI is optional regardless of EFBDN's presence.
Option 2: EFCMI's presence depends on the type of BDN entries in EFBDN.
Option 3: EFCMI may be present but its contents are irrelevant if EFBDN is present.
Option 4: EFCMI must always be present if EFBDN is present.
Explanation: The correct answer highlights a crucial specification detail ensuring interoperability and proper functionality in telecom networks. It implies that for any implementation featuring EFBDN (storing BDN entries), the EFCMI (containing comparison method information for those entries) is mandatory, ensuring consistent definition and accessibility of comparison methods when BDN records are utilized.