C.N. Annadurai, founder of the Dravida Munnetra Kazhagam, was Chief Minister of Madras State (renamed Tamil Nadu under him) from 1967 until his death in February 1969.

Statement (a) is correct: his government passed the Hindu Marriage (Madras Amendment) Act, 1967, which gave legal validity to self-respect marriages conducted without priests or rituals.

Statement (c) is correct: the Veeranam scheme to carry water from Veeranam lake to Chennai was conceived under his government in 1967, though it was executed later.

Statement (b) is correct: as Chief Minister he named his economic policy Scientific Socialism, explaining that socialism is not merely about wealth but about striving to create equality; the nationalisation of private bus transport was presented as its first step.

Statement (d) is the incorrect one: the title Arignar was conferred on him by the poet Bharathidasan at a function in Chennai, and Perarignar, the great scholar, grew out of popular usage; it was not a title conferred by Thanthai Periyar.

(d) option is correct.