Solution:
Option (c) is the answer.
Hematite, sometimes spelt haematite, is a common iron oxide compound with the formula Fe₂O₃ that may be found in a variety of rocks and soils. Hematite crystals are the alpha polymorph of Fe₂O₃ and belong to the rhombohedral lattice system. Its crystal structure is similar to that of corundum and ilmenite.