Your job at a large scientific institution is moving along nicely. It is at the forefront of the latest research on nano-technology, of which you have become very passionate. You have been put in charge of scaling up some existing infrastructure which currently has 9 EC2 instances running in a Cluster Placement Group. All these 9 instances were initially launched at the same time and seem to be performing as expected. You decide that you need to add 2 new instances to the group; however, when you attempt to do this you receive a 'capacity error'. Which of the following actions will most likely fix this problem? Choose the correct answer: