It is because the inventions or the theories formulated by Isaac Newton is more of real life things which could be more or less be seen and is of common sense. The physics of this real objects is known as classical mechanics. Mostly classical mechanics is enriched with Newtonian laws , Hamiltonians and Lagrangian approach. In 1905 three papers were published by Einstein which led to a hell of new discoveries and the discoveries and theories followed is under the branch of modern Physics. Hence, option D is the correct answer.