A developer's leaked API key is used to spin up 400 cryptocurrency mining instances in your AWS account overnight. The monthly bill is now $180K over budget. What should the incident responder do FIRST?
A. Terminate all unauthorized instances to stop the financial bleeding
B. Rotate the compromised API key and disable the associated IAM user
C. Snapshot the instances and preserve CloudTrail logs for forensic analysis
D. Contact AWS billing to request a fraud-related credit