Correct option is D
In a landmark case of Randhir Singh Vs. Union of India, the Supreme Court held that "Construing Article 14 and 16 in the light of the preamble and Article 39 (d) we are of the view that the principle 'Equal pay for equal work' is deducible from those Article and may be properly applied to cases of unequal scales of pay based on no classification or irrational classification though these drawing the different scales of pay do identical work under the same employer." Thus the correct answer is option (d).