The key constraint is no changes to the Lambda code, while still fanning out notifications so that each department receives only its relevant file locations in its existing SQS queue. The cleanest “plumbing-only” pattern is S3 → SNS → SQS with SNS subscription filter policies.

Amazon S3 event notifications can publish events to an SNS topic. SNS then delivers messages to multiple subscribers, including SQS queues. By subscribing each department’s SQS queue to the SNS topic, the system can fan out the event to all queues. To ensure each department receives only its relevant events, the developer can configure SNS subscription filter policies (for example, based on object key prefixes like /deptA/, /deptB/). This routes messages without requiring any change to the Lambda function.

Option D is not ideal because S3 event notifications do not provide the same flexible filtering/routing to multiple SQS queues as SNS filter policies do (and configuring many direct notifications becomes harder to manage).

Options B and C require Lambda code changes, which violates the requirement.

Therefore, use S3 event notifications to SNS, subscribe each department SQS queue, and use filter policies for routing.