Which products make up the current family of HP Desktop Z Workstations?

A.
HP Z440. HP Z640, HP Z660, and HP Z840 Desktop Z Workstations

B.
HP Z230, HP Z640. HP Z820. and HP Z840 Desktop Z Workstations

C.
HP Z230. HP Z420, HP Z640. and HP Z840 Desktop Z Workstations

D.
HP Z230. HP Z440. HP Z640. and HP Z840 Desktop Z workstations