A company monitors its account activity using AWS CloudTrail, and is concerned that some log files are being tampered with after the logs have been delivered to the account's Amazon S3 bucket.
Moving forward, how can the SysOps Administrator confirm that the log files have not been modified after being delivered to the S3 bucket?

A. Stream the CloudTrail logs to Amazon CloudWatch Logs to store logs at a secondary location.
B. Enable log file integrity validation and use digest files to verify the hash value of the log file.
C. Replicate the S3 log bucket across regions, and encrypt log files with S3 managed keys.
D. Enable S3 server access logging to track requests made to the log bucket for security audits.