The correct option is C Fullerene
Graphite is insoluble in water as well as other organic solvents as carbon forms non-polar covalent bonds when it bonds to itself, in graphite.
Diamond is insoluble in water. It does not conduct electricity. Every atom in a diamond is bonded to its neighbours by four strong covalent bonds, leaving no free electrons and no ions.
Similarly, charcoal is insoluble in water and organic solvents.