What happens if no file name is specified in AWS S3 data stream during ingestion?

What happens if no file name is specified in AWS S3 data stream during ingestion?
A . The system does not fetch any file and the data stream shows an error.
B. The system chooses the first file found in the S3 bucket
C. The ingestion setup can’t be completed without specifying the filename.
D. The ingestion setup is completed but the data stream shows 0 records

Answer: B