A user is using an EBS backed instance. Which of the below mentioned statements is true?

A.
The user will be charged for volume and instance only when the instance is running

B.
The user will be charged for the volume even if the instance is stopped

C.
The user will be charged only for the instance running cost

D.
The user will not be charged for the volume if the instance is stopped

Explanation:
If a user has launched an EBS backed instance, the user will be charged for the EBS volume even though the instance
is in a stopped state. The instance will be charged for the EC2 hourly cost only when it is running.
http://docs.aws.amazon.com/AWSEC2/latest/UserGuide/ebs-detaching-volume.html