Xen is classified as a Type 1 (bare-metal) hypervisor, meaning it runs directly on the system hardware rather than on top of a host operating system. Virtualization documentation defines Type 1 hypervisors as having direct control over CPU, memory, and hardware resources, providing better performance and stronger isolation compared to Type 2 hypervisors.
In a Xen-based system, the hypervisor is loaded first during boot. A privileged management domain, known as Domain 0 (Dom0), is then started to manage hardware access and virtual machine lifecycle operations.
This architecture clearly differentiates Xen from hosted (Type 2) hypervisors such as VirtualBox.
Xen is not merely a management tool or application virtualization platform; it is a full hypervisor used in enterprise, cloud, and service provider environments. Therefore, the correct answer is B.