While implementing cost-cutting measurements in your organization, you have been told that you need to migrate some of your existing resources to another region. The first task you have been given is to copy all of your Amazon Machine Images from Asia Pacific (Sydney) to US West (Oregon). One of the things that you are unsure of is how the SSH keys on your Amazon Machine Images need to be migrated. Which of the following best describes how your SSH keys are affected when AMIs are migrated between regions? Choose the correct answer from the options below.

Answer options:

A.The SSH keys will also be copied across, so you don`t need to do anything except launch the new instance.
B.The SSH keys will also be copied across. However, they will only work for users who have already accessed them in the old region. If you need new users to access the instances, then new keys will need to be generated.
C.Neither the SSH key nor the authorized key is copied and consequently you need to create new keys when you launch the new instance.
D.The SSH keys will not be copied to the new region but the authorization keys will still be in the operating system of the AMI. You need to import the SSH keys to the new region if you want to launch the new EC2 instances with the same SSH keys.

Answer – D
Option A is incorrect because, as mentioned above, the SSH Keys are private keys and are never copied across the regions.
Option B is incorrect because the SSH keys are not user-specific.
Option C is incorrect because the authorization keys are copied across the region.
Option D is CORRECT because the authorization key is included in the AMI, hence copied across the region. However, the SSH keys are not copied and need to be imported explicitly if you still want to use the same SSH key for the instances in the new region. See the AWS Console option for importing the SSH key.
For more information on EC2 key pairs, please visit the below URL-
http://docs.aws.amazon.com/AWSEC2/latest/UserGuide/ec2-key-pairs.html
For more information on this subject, please visit the below forums on AWS-
https://forums.aws.amazon.com/thread.jspa?threadID=52654
Note: 
You specify the name of the key pair when you launch an EC2 instance and provide the private key when you connect to that instance. Authorization Key here is the public key content (of the key pair) placed in an entry within ~/.ssh/authorized_keys of that EC2 instance. This gets copied as part of the AMI.