Which of the following cable types is required to run through an air duct?

A.
UTP

B.
Fiber

C.
PVC

D.
Plenum

Explanation:
Plenum rated cable has a special insulation that has low smoke and low flame
characteristics. Plenum cable is mandated to be installed in any “air handling” space. For
example, most large office buildings use the ceiling to return air to the AC unit. This qualifies this
ceiling as a plenum ceiling, and all the cables that go through that ceiling must be plenum rated.