Answer: Correct Option (c) Carbon
Some compounds may take on several physical forms. The arrangement of atoms in crystalline solids differs. Allotropes are a kind of material.
Physical qualities like colour and hardness vary, but chemical properties are typically similar.
Carbon is available in three distinct allotropic forms. Diamond, Graphite, and Buckminsterfullerene are the three materials. Buckminsterfullerene is a kind of carbon that is allotropic. Hence, Option C i.e., Carbon would be the correct response.