M.C Rajah of Madras was the first elected president of-

The correct answer is 'All India Depressed Classes Association' Key Points All India Depressed Classes Association: The All India Depressed Classes Association was founded to represent the interests of the Depressed Classes (now referred to as Scheduled Castes) in India. M.C. Rajah, a prominent leader from Madras, was the first elected president of this association. The association aimed to address social inequalities and promote the rights and welfare of the Depressed Classes, emphasizing issues such as education, employment, and political representation. Additional Information All Assam Students Union: The All Assam Students Union (AASU) is a student organization in Assam, India, known for its role in the Assam Movement during the 1970s and 1980s, which sought to address the issues of illegal immigration and the rights of indigenous people of Assam. It is not related to the Depressed Classes or their representation at an all-India level. Indian National Congress: The Indian National Congress (INC) is one of the two major political parties in India and played a pivotal role in the Indian independence movement. It was not specifically focused on the Depressed Classes, although it did include their issues within its broader agenda for social reform and national independence. British Indian Association: The British Indian Association was established in 1851 in Kolkata to promote the interests of Indians within the British colonial framework. It was not specifically focused on the Depressed Classes and operated more as a forum for the Indian elite to engage with British authorities.