Which of the Following Statements About Domains Is True

Which of the following statements about domains is true?

A) A computer can be a member of both a workgroup and a domain at the same time.
B) Only one domain can exist on a network.
C) If a domain user account needs to be removed, it has to be removed only from the domain database on the domain controller and not each domain member computer.
D) The computer and the domain do not need to be identified by unique names.