Your network has four hyper-v hosts, which are running three domain controllers and about 10 member servers. three of the member servers named hr1, hr2, and hr3 are running on a windows server 2012 r2 hyper-v host; the others are running on windows server 2016 hyper-v hosts. all vms are running windows server 2016. you are currently running an enterprise human resources application on the hr1, hr2, and hr3 servers. you are considering upgrading this application to a new version that was recently released. before you proceed with the upgrade, you set up a test environment consisting of a windows server 2016 hyper-v host and three vms. you haven't been using checkpoints on any of your vms, but you want to start doing so as an extra form of disaster recovery in the event of vm corruption or errors introduced by updates. on your test environment, you want to use checkpoints while you are testing the new application. what type of checkpoints should you use throughout your live network and test network? explain your answer.