The correct answer is (b).
The concurrent list is a list of subjects that are both within the jurisdiction of the central government and the state governments. This means that both the central government and the state governments can make laws on these subjects. The concurrent list was borrowed from the Constitution of Switzerland.
The Constitution of the United States does not have a concurrent list. The Constitution of Australia has a concurrent list, but it is much shorter than the concurrent list in the Indian Constitution. The Constitution of the U.S.S.R. did not have a concurrent list.
The concurrent list is important because it allows the central government and the state governments to work together on important issues. For example, the central government and the state governments can both make laws on education, health, and agriculture. This cooperation is important for the development of the country.
The concurrent list is also important because it protects the rights of the states. The states have a lot of autonomy in India, and the concurrent list helps to ensure that this autonomy is not eroded. The concurrent list is a key feature of the Indian Constitution, and it has played an important role in the development of the country.