Which virtual machine setting should you configure?

Your network contains an Active Directory domain named contoso.com. The domain
contains a server named Server1 that runs Windows Server 2012 R2.Server1 has the
Hyper-V server role installed. The domain contains a virtual machine named VM1.
A developer wants to attach a debugger to VM1.
You need to ensure that the developer can connect to VM1 by using a named pipe.
Which virtual machine setting should you configure?

A.
BIOS

B.
Network Adapter

C.
COM 1

D.
Processor

Explanation:
Named pipes can be used to connect to a virtual machine by configuring COM 1.
References:
http://support.microsoft.com/kb/819036
http://support.microsoft.com/kb/141709