Vicki works from home developing apps for managing highly regulated data, such as patients' medical history or customers' payment information. She's always concerned with prioritizing data security and ensuring that no programming loopholes would allow hackers access to data managed by one of her apps. During the development process, Vicki performs some initial, lightweight testing of her apps in a few OS environments running in VMs on her home computer, and then she passes each app along to a team at another location for more intense and thorough testing. Which hypervisor is Vicki most likely using? a. ESXi b. Windows Server 2016 c. XenServer d. VirtualBox