Out of the given options, only Dr. B. R. Ambedkar attended all the three Round Table Conferences. The Round Table Conferences were a series of negotiations between the British government and various political leaders of India, held in London between 1930 and 1932, to discuss constitutional reforms for India. These conferences aimed to find a solution to the political deadlock and to address the demands of different parties and communities in India. Although leaders like Jawaharlal Nehru, Vallabhbhai Patel, and Dr. Rajendra Prasad played crucial roles in the Indian Independence movement, they did not attend all the three Round Table Conferences. It is important to note that the Round Table Conferences were significant in shaping India`s political future and the negotiations paved the way for the Government of India Act of 1935.