Correct answer: B. 1856 CE
Explanation: The direct answer is B: the Hindu Widows’ Remarriage Act was passed in 1856. The law legally permitted Hindu widows to remarry, challenging a harmful social restriction. Ishwar Chandra Vidyasagar strongly supported this reform through scholarship and public advocacy, and the colonial government enacted the law in 1856. Step by step: widow remarriage was socially opposed in many communities; reformers argued for change; legislation was introduced; the 1856 Act recognised remarriage as legally permitted. Option B is correct. Option A, 1829, refers to the Bengal Sati Regulation associated with the abolition of sati, not widow remarriage. Option C, 1857, is the year commonly associated with the Revolt of 1857, not this Act. Option D, 1885, is associated with the founding of the Indian National Congress, not widow-remarriage legislation. The memory chain is: sati abolition 1829, widow remarriage 1856, Congress 1885.