Final answer:
In data centers, the most commonly used hypervisor is the Type 1 or bare-metal hypervisor due to its efficiency and direct access to the host hardware, which provides better performance and stability.
Step-by-step explanation:
The type of hypervisor most likely to be used in a data center is a Type 1 hypervisor, which is also known as a bare-metal hypervisor. Type 1 hypervisors run directly on the host's hardware to control the hardware and to manage guest operating systems. In contrast, a Type 2 or hosted hypervisor runs on a conventional operating system just like any other software application. Data centers prioritize efficiency, stability, and performance, all of which are characteristics of Type 1 hypervisors due to their direct access to physical hardware without an intermediary operating system, hence their prevalence in these environments.