Question: In the EFOPL (Operator PLMN List) file, what does a BCD value of 'D' in any of the MCC and/or MNC digits indicate for the corresponding MCC/MNC digit?
Option 1: A reserved value for future use
Option 2: An error in the MCC/MNC configuration
Option 3: The need to fetch the MCC/MNC from another source
Option 4: A 'wild' value, allowing any MCC/MNC digit to match
Explanation: According to EFOPL specifications, a BCD value of 'D' in any MCC and/or MNC digits indicates a 'wild' value, meaning any value will be considered a match for that digit, providing flexibility in defining PLMN entries.