Which of the following are interstitial carbides?

The correct option is C $WC$
Interstitial carbides are derived primarily from relatively large transition metals that act as a host lattice for the small carbon atoms, which occupy the interstices of the close-packed metal atoms.

Interstitial carbides are characterized by extreme hardness but at the same time extreme brittleness. They have very high melting points and retain many of the properties associated with the metal itself, such as high conductivity of heat and electricity as well as metallic lustre. Examples of interstitial carbides are ZrC (Zirconium Carbide), VC (Vanadium Carbide) and WC (Tungsten Carbide).