CloudTrail has been enabled in your AWS account, and the CloudTrail logs are saved in a CloudWatch Log group. You want to create a metric filter in the log group that can filter all the EC2 Auto Scaling API calls, including the operations on Auto Scaling groups and Launch Configurations. How would you define the filter pattern in the metric filter?

Answer options:

A.Filter the "eventsource" to be "autoscaling.amazonaws.com".
B.Filter the "eventName" to be "autoscaling".
C.Filter the "AutoScalingGroupName" to be "*".
D.Filter the "eventType" to be "*".

Correct Answer: A
Option A is CORRECT because, in CloudTrail logs, the "eventsource" of the EC2 Auto Scaling API calls is "autoscaling.amazonaws.com". Users can filter the Auto Scaling logs based on the "eventsource" field.
Option B is incorrect because, for EC2 Auto Scaling API calls, the "eventName" can have lots of possible values such as "CreateLaunchConfiguration" and "DetachLoadBalancers". Filtering "eventName" to be "autoscaling" is incorrect.
Option C is incorrect because the Auto Scaling API logs may not include the "AutoScalingGroupName" field. Please check the API log example in the following reference.
Option D is incorrect because this option does not filter the EC2 Auto Scaling API calls from the CloudTrail logs.
References:
https://docs.aws.amazon.com/autoscaling/ec2/userguide/logging-using-cloudtrail.html
https://docs.aws.amazon.com/AmazonCloudWatch/latest/logs/FilterAndPatternSyntax.html