The correct option is C Judiciary
For a long time, the same party ruled both at the Centre and in most of the States. This meant that the State governments did not exercise their rights as autonomous federal units. As and when the ruling party at the State level was different, the parties that ruled at the Centre tried to undermine the power of the States. All this changed significantly after 1990. This period saw the rise of regional political parties in many States of the country. Since no single party got a clear majority in the Lok Sabha, the major national parties had to enter into an alliance with many parties including several regional parties to form a government at the Centre. This led to a new culture of power sharing and respect for the autonomy of State Governments. This trend was supported by a major judgement of the Supreme Court that made it difficult for the Central Government to dismiss state governments in an arbitrary manner.