The four most important Indians of the twentieth century

I am currently of the opinion that the four most important Indians of the twentieth century were

a) Mohandas K Gandhi,
b) a man who followed Gandhi, Jawaharlal Nehru,
c) a man who funded Gandhi, Ghanshyam Das Birla, and
d) a man who was a Gandhian in his school days, Dhirajlal Ambani.