Explanation:

December 1920 at the Nagpur session of the Indian National Congress—
The programme of non-cooperation was endorsed;
An important change was made in Congress creed: now, instead of having the attainment of self-government through constitutional means as its goal, the Congress decided to have the attainment of swaraj through peaceful and legitimate means, thus committing itself to an extraconstitutional mass struggle;
Some important organizational changes were made: a Congress Working Committee (CWC) of 15 members was set up to lead the Congress from now onwards; Provincial Congress Committees on linguistic basis were organized; ward committees was organized; and entry fee was reduced to four arenas;
Gandhi declared that if the non-cooperation programme was implemented completely, swaraj would be ushered in within a year.