The correct answer to the question is option 2, Mahatma Gandhi. He is the author of the book Hind Swaraj.

To better understand the options, let`s take a look at each one:

- Option 1: Bal Gangadhar Tilak was an influential figure in the Indian independence movement, but he did not author Hind Swaraj.

- Option 3: Gopal Krishna Gokhale was a political leader and social reformer, but he did not write Hind Swaraj.

- Option 4: M.G. Ranade was a prominent Indian scholar and social reformer, but he did not write Hind Swaraj.

Therefore, the correct answer is option 2, Mahatma Gandhi. Hind Swaraj is a book that Gandhi wrote in 1909. In the book, Gandhi outlines his vision of true freedom and self-governance for India, which he calls Hind Swaraj. It is a significant work in the Indian independence struggle and provides insights into Gandhi`s philosophy and principles.