The Growth of mass nationalism

After 1919 the struggle against British rule gradually became a mass movement involving pasants tribals students and woman in large numbers and occasionally factory workers are as well. Certain business groups too began to actively support the Congress in the 1920 why was this so?  The first world war altered the economic and political situation in India it led to a huge rise in the defence expenditure of the goverment of India the goverment in turn increased taxes on individual incomes and business profits increased military expenditure and the demands for war supplies led to a sharp rise in prices which created great difficulties for the common people on the other hand business groups reapedbfabulous profits from the war.