The correct option is C Crystallin
Crystallin is a water-soluble structural protein, found in the lens and the cornea of the eye accounting for the transparency of the structure. The crystallins are water-soluble structural proteins that occur in high concentration in the cytoplasm of eye lens fibre cells. Four major groups of crystallin have been distinguished on the basis of size, charge and immunological properties: alpha-, beta- and gamma-crystallins occur in all vertebrate classes (though gamma-crystallins are low or absent in avian lenses); and delta-crystallin is found exclusively in reptiles and birds.