A company wants to log every write to an S3 bucket into another S3 bucket in the same Region. Which option requires the least operational effort?

Creating a CloudTrail data event trail is the most operationally efficient solution. CloudTrail natively captures S3 object-level API activity (data events) such as PutObject, CopyObject, and DeleteObject, and can deliver these logs directly to an S3 bucket. This eliminates the need for custom Lambda functions or Kinesis Data Firehose, significantly reducing operational overhead. The incorrect options involve more complex architectures: Using S3 Event Notifications with Lambda and Kinesis Data Firehose adds multiple components that require configuration, monitoring, and maintenance. Using S3 Event Notifications with Lambda directly to S3 still requires developing and maintaining a Lambda function. Using CloudTrail management events is incorrect because management events track control plane operations (e.g., creating a bucket), not data plane operations like object writes.