Which one of the following statements regarding hosted virtualization versus bare$-$metal virtualization is CORRECT.

a$.$ Bare$-$metal virtualization uses a type $2$ hypervisor in which the host OS $($Operating System$)$ accesses host hardware on behalf of the guest OS$.$ It is used mostly for desktop virtualization solutions. Hosted virtualization is used mainly for server virtualization in data centres and uses a type $1$ hypervisor.

b$.$ Hosted virtualization uses a type $2$ hypervisor in which the host OS accesses host hardware on behalf of the guest OS$.$ It is used mostly for desktop virtualization solutions. Bare$-$metal virtualization is used mainly for server virtualization in data centres and uses a type $1$ hypervisor.