Question: Upon receiving a FurnishChargingInformationSMS operation, what action does the smsSSF take regarding the free-format information if a Logical SMS record already exists?
Option 1: Deletes the existing Logical SMS record and creates a new one with the received information.
Option 2: Appends the new free-format information to the existing data in the Logical SMS record by default.
Option 3: Overwrites the free-format data previously written in the Logical SMS record with the newly received information by default.
Option 4: Ignores the new free-format information if a Logical SMS record already contains data.
Explanation: According to the specified behavior, when an smsSSF receives a FurnishChargingInformationSMS operation and a Logical SMS record already exists, it overwrites the previously written free-format data with the new information by default. However, it's also noted that appending is possible, but this is not the default behavior as described in the context of this question.