Which query should you use?

Your network contains a System Center 2012 Configuration Manger environment.
You need to create a collection that contains all of the virtual machines.
Which query should you use?

A.
select * from SMS_R_System
where SMS_R_System.ResourceID not in
(select ResourceID from SMS_R_System
where SMS_R_System.IsVirtualMachine != 1)

B.
select * from SMS_R_System
where SMS_R_System.IsVirtualMachine != 1

C.
select * from SMS_R_System
where SMS_R_System.IsVirtualMachine = 1

D.
select * from SMS_R_System
where SMS_R_System.ResourceID not in
(select ResourceID from|SMS_R_System
where SMS_R_System.IsVirtualMachine = 1)

Explanation:
The SMS_R_System Server WMI Class include the following method:
IsVirtualMachine
Data type: Boolean
Access type: Read-only
Qualifiers: None
True if the resource is a virtual machine.