The person known as Lokahitavadi is G.H. Deshmukh. G.H. Deshmukh was a prominent social reformer and journalist from Maharashtra, India. He is well-known for his efforts towards social welfare and for his advocacy on various issues related to the welfare of the people.

Option 2, G.K. Gokhale, was also a prominent figure in Indian politics and a social reformer, but he is not known as Lokahitavadi. Gokhale is known for his efforts towards political reform and education.

Option 3, J.G. Phule, is an important figure in the social reform movement in Maharashtra, known for his efforts towards women`s rights and caste equality. However, he is not known as Lokahitavadi.

Option 4, M.G. Ranade, was a scholar, social reformer, and politician. He played a significant role in social and educational reforms in the late 19th century. However, he is not known as Lokahitavadi.

Therefore, the correct answer is option 1, G.H. Deshmukh, who is known as Lokahitavadi.