Which of the following Acts converted Unicameral Legislature of Bihar into Bicameral : Bihar Legislative Assembly and Bihar Legislative Council ?

Under the constitutional devolution scheme introduced by the Government of India Act 1919 (Montagu-Chelmsford Reforms), the Bihar and Orissa Legislative Council was reconstituted with an elected majority alongside executive mechanisms, initiating the bicameral restructuring of regional provincial governance. BPSC officially designated the Government of India Act 1919 (option B) as the correct answer.