GMPLS is based upon:

A.
VPI/VCI-based switching devices

B.
Non-Packet-based devices

C.
Packet-based switching devices

D.
None of the above

Explanation:
The Generalized Multi-Protocol Label Switching (GMPLS)[1] is a protocol suite extending MPLS to
manage further classes of interfaces and switching technologies other than packet interfaces and
switching, such as time division multiplex, layer-2 switch, wavelength switch and fiber-switch.
GMPLS is composed of three main protocols:

Resource Reservation Protocol with Traffic Engineering extensions (RSVP-TE) signaling
protocol.[5][6]
Open Shortest Path First with Traffic Engineering extensions (OSPF-TE) routing protocol.[7][8]
Link Management Protocol (LMP).[9]