How Do Virtual COM Ports Communicate with the Host Machine

Multiple Choice

How do virtual COM ports communicate with the host machine on Hyper-V?

A) COM ports communicate via special TCP/IP enabled network adapters on the guest and the host.
B) The serial ports must utilize a special Microsoft USB driver that passes the traffic on the host's USB bus.
C) Communication occurs through a setting in the Windows registry.
D) Communication is done through the use of a named pipe.