(a) Carbon is the element 'E' which exists in three allotropic forms A, B and C.
(b) Buckminsterfullerene is the allotrope, A, of carbon in which the atoms are joined to form spherical molecules.
(c) Graphite is the allotrope, B, of carbon which is surrounded by three other carbon atoms to form a sheet like structure.
(d) Diamond is the allotrope, C, of carbon in which each atom is surrounded by four other carbon atoms to form a rigid structure.
(e) The allotrope C (Diamond) is used to make jewellery.
(f) The allotrope B (Graphite) is used in making anode of a dry cell.