A t2.medium EC2 instance type must be launched with what type of Amazon Machine Image
(AMI)?

A.
An Instance store Hardware Virtual Machine AMI

B.
An Instance store Paravirtual AMI

C.
An Amazon EBS-backed Hardware Virtual Machine AMI

D.
An Amazon EBS-backed Paravirtual AMI

Explanation:
You must launch a T2 instance using an HVM AMI. For more information, see Linux AMI
Virtualization Types.
You must launch your T2 instances using an EBS volume as the root device. For more
information, see Amazon EC2 Root Device Volume.
http://docs.aws.amazon.com/AWSEC2/latest/UserGuide/ec2-instance-resize.html