Question: In a Universal Subscriber Identity Module (USIM) application, what is the purpose of the 'Comparison Method Identifier' byte in the EFCMI file, and how is its interpretation defined?
Option 1: It specifies the comparison method for BDN records; its interpretation is defined by the card issuers implementing the BDN feature on their USIMs.
Option 2: It determines the coding scheme for alpha-tagging in EFADN; its interpretation is standardized across all USIM applications.
Option 3: It indicates the availability of service n° 6; its interpretation is reserved for future use.
Option 4: It stores the list of available services on the USIM; its interpretation varies based on the mobile network operator.
Explanation: The 'Comparison Method Identifier' byte in the EFCMI file specifies the comparison method for BDN records. Its interpretation is not standardized but rather defined by the USIM card issuers who implement the BDN feature, highlighting the flexibility given to manage specific aspects of USIM functionality.