निम्नलिखित भारतीय नेताओं में से किसने लंदन में आयोजित तीनों गोलमेज सम्मेलनों (1930-1932) में भाग लिया था?

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?