A user has launched an EBS backed instance. The user started the instance at 9 AM in the morning. Between
9 AM to 10 AM, the user is testing some script. Thus, he stopped the instance twice and restarted it. In the
same hour the user rebooted the instance once. For how many instance hours will AWS charge the user?

A.
3 hours

B.
4 hours

C.
2 hours

D.
1 hour

Explanation:
A user can stop/start or reboot an EC2 instance using the AWS console, the Amazon EC2 CLI or the Amazon
EC2 API. Rebooting an instance is equivalent to rebooting an operating system. When the instance is rebooted
AWS will not charge the user for the extra hours. In case the user stops the instance, AWS does not charge
the running cost but charges only the EBS storage cost. If the user starts and stops the instance multiple times
in a single hour, AWS will charge the user for every start and stop. In this case, since the instance was
rebooted twice, it will cost the user for 3 instance hours.