A user has launched a large EBS backed EC2 instance in the US-East-1a region. The user wants to achieve Disaster Recovery (DR), for that instance, by creating another small instance in Europe. How can the user achieve DR?

Answer options:

A.Copy the running instance using the “Instance Copy” command to the EU region.
B.Create an AMI of the instance and copy the AMI to the EU region. Then launch the instance from the EU AMI.
C.Copy the instance from the US East region to the EU region.
D.Use the “Launch more like this” option to copy the instance from one region to another.

Answer – B
Options A and C are incorrect because you cannot directly copy the instance. You need to create an AMI from the instance.
Option B is CORRECT because if you need an AMI across multiple regions, you have to copy the AMI across regions. Note that, by default, AMI’s that you have created will not be available across all regions.
Option D is incorrect because using "Launch More Like This..." enables you to use a current instance as a base for launching other instances in the same availability zone. It does not clone your selected instance; it only replicates some configuration details. First, create a copy of your instance, create an AMI from it, and then launch more instances from the AMI.
For the entire details to copy AMI’s, please visit the link - 
http://docs.aws.amazon.com/AWSEC2/latest/UserGuide/CopyingAMIs.html