The correct answer is option 2: Tenth Schedule.

The Tenth Schedule of the Indian Constitution contains the Anti-Defection Act. The Anti-Defection Act was introduced to address the issue of political defections and the instability it caused in the political system.

Option 1: Twelfth Schedule refers to the Schedule that lists the powers and functions of the municipalities.

Option 3: Ninth Schedule contains laws that are immune from judicial review.

Option 4: Seventh Schedule of the Indian Constitution deals with the division of powers between the Union and the States.

Therefore, the correct answer is option 2: Tenth Schedule.