The correct answer is (a) Antidefection Law.
The Tenth Schedule of the Indian Constitution is also known as the Anti-Defection Law. It was added to the Constitution in 1985 with the objective of preventing defections in Parliament and State Legislatures. The law provides for the disqualification of a member of Parliament or State Legislature if he/she voluntarily gives up his/her membership of a political party or joins another political party without the prior permission of his/her party. The law also provides for the disqualification of a member if he/she votes against his/her party on a motion of confidence or no-confidence.
The Tenth Schedule has been amended several times since it was enacted. The most recent amendment was made in 2003. The amendment has made the law more stringent by reducing the number of members required to form a separate group from one-third to one-fourth of the total strength of the House.
The Tenth Schedule has been successful in preventing defections in Parliament and State Legislatures. However, it has also been criticized for being too harsh and for stifling dissent.
The other options are incorrect.
(b) Panchayati Raj is a system of local self-government in India. It was introduced in 1992 with the objective of decentralization of power and empowerment of the people. Panchayati Raj institutions are elected bodies at the village, block, and district levels.
(c) Land reforms are measures taken by the government to improve the condition of landless laborers and farmers. These measures include the redistribution of land, the abolition of tenancy, and the consolidation of holdings.
(d) Languages are a very important part of Indian culture and identity. The Constitution of India recognizes 22 official languages. The government has also taken steps to promote the use of these languages in education, administration, and the media.