The answer is Ishwar Chandra Vidyasagar. He was born in 1820 in Bengal and grew into one of the defining figures of the Bengal Renaissance, working as a Sanskrit scholar, teacher, writer, printer and reformer all at once. He famously lived by the idea of simple living and high thinking, and much of his energy went toward challenging the social restrictions of his time, most notably the ban on widows remarrying under orthodox Hindu practice.
His persistent campaigning is what pushed the government to pass the Hindu Widows' Remarriage Act on 26th July 1856, legally allowing widows across British India to remarry, a major break from rigid social tradition. Beyond this reform, he also helped reshape and modernize Bengali prose and script, and put real effort into expanding access to education for women.
Checking the other names rules them out clearly. Raja Ram Mohan Roy was another towering reformer of the same broader era, but his legacy centers on abolishing Sati and starting the Brahmo Samaj, and he had already passed away in 1833, well before the 1856 act came into being. Rabindranath Tagore, the poet and Nobel laureate, was not even born until 1861, so he could not be tied to this 1856 reform. Bankim Chandra Chatterjee is remembered for writing Vande Mataram and the novel Anandamath, not for this social reform work. Every clue in the question points specifically to Ishwar Chandra Vidyasagar.
निम्नलिखित ऐतिहासिक तिथियों से सम्बंधित घटनाओं का उल्लेख कीजिए-
(i) 1950 ई०
(ii) 1539 ई०
(iii) 1540 ई०
(iv) 1664 ई०
(v) 1765 ई०
(vi) 1206 ई०
(vii) 1336 ई०
(viii) 1510 ई०
(ix) 1526 ई०
(x) 1875 ई०