Dr. M.S. Swaminathan could produce an amber-seeded high yielding wheat variety called as 'sharbati sonora' from Mexican dwarf variety, by using ?

The correct option is A Radiations of ultraviolet and gamma rays
The mutant variety 'sharbati sonora' was officially approved in 1967. It was developed by irradiation of seeds with gamma rays. Main improved attributes of mutant variety are amber grain color, early maturity and high protein content.

A scientific paper in which Swaminathan and his team claimed to have produced a mutant breed of wheat by gamma irradiation of a Mexican variety (sonora 64) resulting in Sharbati Sonora, claimed to have a very high lysine content led to a major controversy.