Where did Gandhiji initially forge the techniques of Satyagraha?

In which of the following Satyagraha movements, did Gandhiji not participate directly?

Who saved the life of Gandhiji in Bihar during Champaran Satyagraha?

At which place of Bihar, Gandhiji started Satyagraha movement for the first time in India :

Which one of the following was the last step in the Gandhian strategy of Satyagraha?

When did Gandhiji give the slogan of ‘Swaraj in a year’?