What is the effect of running the virsh setvcpus CLUSNODE1 2 command?

What is the effect of running the virsh setvcpus CLUSNODE1 2 command?

A.
It adds 2 virtual CPUs to the virtual machine CLUSNODE1.

B.
It sets virtual machine CLUSNODE1 to have 2 virtual CPUs.

C.
It sets all virtual CPUs of virtual machine CLUSNODE1 to physical processor 2.

D.
It restricts the virtual machine CLUSNODE1 to using, at most, 2 physical processors.