किस घटना के साथ सविनय अवज्ञा आंदोलन की आधिकारिक शुरुआत हुई थी?

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?