The 73rd Constitutional Amendment Act, 1992 constitutionalized Panchayati Raj Institutions and provided for a three-tier system of Panchayats at the village, intermediate, and district levels in every State with a population exceeding twenty lakhs. States with a population not exceeding twenty lakhs may not constitute Panchayats at the intermediate level (Article 243B). Option A correctly describes the core structural reform introduced by the Act for most states.