Final answer:
The correct answer is D) ESXi, a bare metal hypervisor from VMware for hosting virtual machines directly on server hardware without needing an underlying OS. Option D is correct.
Step-by-step explanation:
The commercially available hypervisor from VMware that provides users a bare metal hypervisor to host virtual machines on their servers is D) ESXi.
VMware ESXi is part of VMware's larger suite of server virtualization products, known as vSphere. ESXi installs directly onto the server hardware, providing a minimalist environment for running virtual machines. This type of hypervisor does not require an underlying operating system, which is why it is known as a 'bare metal' hypervisor.
In contrast, other hypervisors may run within a conventional operating system environment, a method known as 'hosted' virtualization. ESXi supports a range of virtualization features including VMotion (the ability to move virtual machines between host servers without service interruption) and high availability. It is favored for its scalability, robustness, and efficiency.