Question: What is the primary purpose of generating CDR files in the offline charging process?
Option 1: To provide real-time feedback to the user about their network resource usage.
Option 2: To perform post-processing functions such as billing mediation and statistics.
Option 3: To affect, in real-time, the service rendered based on charging information.
Option 4: To enable subscriber billing and/or inter-operator accounting by transferring CDR files to the network operator's BD.
Explanation: The primary purpose of generating CDR files in the offline charging process is to enable subscriber billing and/or inter-operator accounting. This is achieved by transferring the CDR files to the network operator's Billing Domain (BD), which typically comprises post-processing systems such as the operator's billing system or billing mediation device.