Explanation:

The correct answer is option 'B', which is the 52nd Amendment to the Constitution of India. This amendment sought to curb political defection in India.

Background:
Political defection refers to the act of elected representatives changing their political party affiliation or leaving their party to join another party. It often leads to instability in the government and undermines the democratic process. In India, political defection has been a significant issue since the early years of independence.

Key Points:

1. 52nd Amendment:
- The 52nd Amendment to the Constitution of India was enacted in 1985.
- It introduced the Tenth Schedule, popularly known as the Anti-Defection Law, in the Indian Constitution.
- The amendment sought to address the problem of political defection by disqualifying elected representatives who defected from their party.
- It aimed to provide stability to the government and promote party discipline.

2. The Anti-Defection Law:
- The Tenth Schedule, introduced by the 52nd Amendment, contains provisions regarding the disqualification of elected members on the grounds of defection.
- According to the law, if an elected member voluntarily gives up the membership of their party or votes against the party's directions, they can be disqualified from holding their office.
- The law applies to both Parliament and state legislatures.
- It prohibits defection by elected members and imposes penalties for defection, including the loss of membership and disqualification from holding any office.
- However, there are certain exceptions to the law, such as when a party merges with another party.

3. Importance and Impact:
- The 52nd Amendment and the Anti-Defection Law have played a crucial role in curbing political defection in India.
- They have helped in maintaining stability in the government and ensuring party discipline.
- By disqualifying defectors, the law acts as a deterrent and discourages elected representatives from switching parties for personal gain or political opportunism.
- The law has also led to legal battles and controversies, with various cases challenging its constitutional validity and interpretation.

In conclusion, the 52nd Amendment to the Constitution of India introduced the Anti-Defection Law, which sought to curb political defection in the country. This amendment and the subsequent law have been instrumental in maintaining stability and promoting party discipline in the Indian political system.