You’ve accidentally deleted the private key for an EBS-backed Amazon Linux EC2 instance. You want to regain access to your instance. What steps must you perform to resolve this issue (Select TWO)?

Answer options:

A.Generate new key pair.
B.Attach root volume to another instance. Update the authorized_keys file on the mounted volume with the new public key.
C.Use curl http://169.254.169.254/latest/meta-data/public-keys/0/openssh-key command to retrieve the EC2 key.
D.Open the Amazon EC2 console. Under NETWORK & SECURITY, choose Key Pairs. Choose Import Key Pair to perform the import key action.
E.Open the Amazon EC2 console. Select the instance, choose Actions, select Instance State, and then choose Recovery Mode.

Answer: A and B
Option A is CORRECT because you must generate a new key pair as a first step to reconnect to a Linux instance on AWS.
Option B is CORRECT because you must attach the root volume to another recovery EC2 instance.You must then copy the new public key to the /home/ec2-user/.ssh/authorized_keys file.
Option C is incorrect because http://169.254.169.254/latest/meta-data/public-keys/0/openssh-key returns the public key associated with the instance.
Option D is incorrect because this imports an existing key pair into the AWS console. It does not import the public key to an EC2 instance.
Option E is incorrect because there is no Recovery Mode option available for connecting back to the EC2 Linux instance with a lost private key.
Reference:
https://docs.aws.amazon.com/AWSEC2/latest/UserGuide/replacing-lost-key-pair.html