Question: In a charging record for an MTC (Mobile Terminated Call) transaction, what does the 'Served MSISDN' field represent?
Option 1: The MSISDN of the calling party's primary number in cases of multi-numbering.
Option 2: The MSISDN of the mobile subscriber being called (the served party).
Option 3: A dynamically assigned IP address for the served IMSI.
Option 4: The MSISDN of the serving network's gateway.
Explanation: In the context of an MTC record, the 'served party' refers to the mobile subscriber who is being called. Therefore, the 'Served MSISDN' field contains the MSISDN of this called subscriber, making Option 2 the correct answer.