You Are Playing Around with Setting Up Stacks Using JSON

You are playing around with setting up stacks using JSON templates in CloudFormation to try and understand them a little better. You have set up about 5 or 6 but now start to wonder if you are being charged for these stacks. What is AWS's billing policy regarding stack resources?

A) You are not charged for the stack resources if they are not taking any traffic.
B) You are charged for the stack resources for the time they were operating (but not if you deleted the stack within 30 minutes)
C) You are charged for the stack resources for the time they were operating (but not if you deleted the stack within 60 minutes)
D) You are charged for the stack resources for the time they were operating (even if you deleted the stack right away)