How does Vagrant run virtual machines?
A. Vagrant uses a vagrant-specific hypervisor called VagrantVM.
B. Vagrant has to be run within a running virtual machine which is not controlled by Vagrant.
C. Vagrant ships with an embedded version of VirtualBox.
D. Vagrant uses so-called provides which control external hypervisors such as VirtualBox.
E. Vagrant generates virtual machine images but does not provide a mechanism to run them.