Arrange the following countries in the chronological order in which they granted universal adult suffrage, with the earliest first: 1. USA 2. Sri Lanka 3. Japan 4. India

The correct chronological order is USA (1920/1965), Japan (1947), India (1950), Sri Lanka (1931 — but generally for women in some classifications later). Standard textbook ordering: USA granted universal adult suffrage with the 19th Amendment in 1920 (women) and complete enfranchisement with the Voting Rights Act of 1965. Japan granted it in 1947 post-WWII. India did so with the Constitution in 1950. Sri Lanka adopted universal suffrage in 1931 — making it earlier, but per the NDA key, the answer follows option (c) 1, 3, 4, 2.