Answer – B
The AWS Documentation mentions the following.
Using CloudWatch Events, you can monitor jobs` progress, build AWS Batch custom workflows with complex dependencies, generate usage reports or metrics around job execution, or build your own custom dashboards. With AWS Batch and CloudWatch Events, you can eliminate scheduling and monitoring code that continuously polls AWS Batch for job status changes. Instead, handle AWS Batch job state changes asynchronously using any CloudWatch Events target, such as AWS Lambda, Amazon Simple Queue Service, Amazon Simple Notification Service, or Amazon Kinesis Data Streams.
Option A is incorrect since this is an API Monitoring service.
Option C is incorrect since this is used to monitor configuration changes.
Option D is incorrect since this is used as a messaging service.
For more information on the Cloudwatch event stream, please refer to the below URL-
https://docs.aws.amazon.com/batch/latest/userguide/cloudwatch_event_stream.htm