The correct answer is option 4, Bal Gangadhar Tilak. Bal Gangadhar Tilak was an eminent figure in the Indian independence movement. He was one of the key leaders who advocated for Swarajya, meaning self-rule or independence, in the political sense. Tilak believed in the importance of mobilizing the masses and creating a sense of national pride and unity among Indians.

Tilak also played a significant role in promoting the use of Hindi as the national language of India. He emphasized the cultural and linguistic heritage of the Hindi language and believed that it would strengthen national identity. Tilak used Hindi extensively in his writings, speeches, and newspapers to reach a wider audience and disseminate his ideas effectively.

It is important to note that while Tilak popularized the term Swarajya and promoted Hindi, Mahatma Gandhi also played a crucial role in these movements. Gandhi`s philosophy of non-violent resistance, called Satyagraha, became synonymous with the struggle for Swarajya. Additionally, Gandhi advocated for the use of Hindustani, a mix of Hindi and Urdu, as the national language, promoting linguistic unity among Hindus and Muslims.