Under which one of the following Constitution Amendment Acts, four languages were added to the languages under the Eighth Schedule of the Constitution of India, thereby raising their number to 22?

The Constitution (Ninety-second Amendment) Act, 2003 added four languages — Bodo, Dogri, Maithili and Santhali — to the Eighth Schedule, thereby raising the total number of constitutionally recognised languages to 22 [1]. Official government records and releases likewise confirm that these four languages were included by the 92nd Amendment (published in the Gazette in January 2004), and list the full set of 22 scheduled languages while noting earlier additions such as Sindhi (1967) and Konkani, Manipuri and Nepali (1992) [2]. Thus the correct amendment is the Ninety-second Amendment Act, 2003 (Option 3).

Sources

1. [1] Indian Polity, M. Laxmikanth(7th ed.) > Chapter 92: World Constitutions > APPENDIX IV Constitutional Amendments at a Glance > p. 724
2. [2] https://www.pib.gov.in/newsite/erelcontent.aspx?relid=5928