Answer : 4. "He is a Vaidya/Ayurvedic doctor"
Explanation :

Tamil Nadu Chief Minister M.K. Stalin unveiled a statue of leading anti-caste activist Ayothi Thas Pandithar in Chennai in December 2023. The construction of the statue and memorial cost Rs 2.49 crore. Stalin praised Ayothi Thas as a pioneer of Periyar in popularizing the terms ‘Tamizan’ and ‘Dravidian’ identities politically. Born in Madras in 1845, Ayothi Thas promoted Dravidian ideology through the Dravida Mahajana Sabha, founded with Retamalai Srinivasan in 1891. In 1876, Thas had founded the Advaidananda Sabha and launched the magazine “Dravida Pandyan” with Rev. John Rathina. A prominent activist and accomplished medical practitioner, he organized the Nilgiri Hills tribes into the independence movement in the 1870s. His most revolutionary declaration in 1886 was that the Scheduled Castes were not Hindus, which inspired their separate socio-political mobilization. This declaration laid the groundwork for the later Dravida Kazhagam. Thas urged Dalits to register as “casteless Dravidians” in the 1891 census. His anti-caste activities also inspired Anagarika Dharmapala of Sri Lanka. Eöthi Thaas died on May 5, 1914, after a life dedicated to social justice.