भारतीय इतिहास की किस घटना ने सविनय अवज्ञा आंदोलन की औपचारिक शुरुआत को चिह्नित किया?

The Karachi Session of the Indian National Congress was held in the year ________ and was presided over by ________.

Where was the 'India House' organization, founded by Shyamji Krishna Varma in the early twentieth century, based?