A Developer's laptop was stolen. The laptop was not encrypted, and it contained the SSH key used to access multiple Amazon EC2 instances. A SecurityEngineer has verified that the key has not been used, and has blocked port 22 to all EC2 instances while developing a response plan.
How can the Security Engineer further protect currently running instances?

A. Delete the key-pair key from the EC2 console, then create a new key pair. B. Use the modify-instance-attribute API to change the key on any EC2 instance that is using the key. C. Use the EC2 RunCommand to modify the authorized_keys file on any EC2 instance that is using the key. D. Update the key pair in any AMI used to launch the EC2 instances, then restart the EC2 instances.