How can this task be accomplished?

A company had one of its Amazon EC2 key pairs compromised. A Security Engineer must identify which current Linux EC2 instances were deployed and used the compromised key pair.

How can this task be accomplished?
A . Obtain the list of instances by directly querying Amazon EC2 using: aws ec2 describe-instances –fi1ters "Name=key-name,Values=KEYNAMEHERE".
B . Obtain the fingerprint for the key pair from the AWS Management Console, then search for the fingerprint in the Amazon Inspector logs.
C . Obtain the output from the EC2 instance metadata using: curl http: //169.254.169.254/latest/meta-data/public- keys/0/.
D . Obtain the fingerprint for the key pair from the AWS Management Console, then search for the fingerprint in Amazon CloudWatch Logs using: aws logs filter-log-events.

Answer: A