What Statement Accurately Describes a Perimeter Network Location

What statement accurately describes a perimeter network location?

A) A perimeter network is a network that is not part of Active Directory.
B) A perimeter network is a network in a different area of the Active Directory forest.
C) Perimeter networks are networks that have automatically installed the VMM Local Agent via Active Directory.
D) Perimeter networks are networks that are isolated in scope and exist in a separate forest using VMM.