**Concurrent List**

The correct answer is option 'A' - Concurrent List.

**Explanation:**

The Constitution of India divides the legislative powers between the central government and the state governments. These powers are categorized into three lists - Union List, State List, and Concurrent List.

1. **Union List**: The Union List consists of subjects on which only the central government has the authority to make laws. Some examples of subjects under the Union List include defense, foreign affairs, currency, atomic energy, etc. The central government has exclusive jurisdiction over these subjects.

2. **State List**: The State List consists of subjects on which only the state governments have the authority to make laws. Some examples of subjects under the State List include public health, police, local government, public order, etc. The state governments have exclusive jurisdiction over these subjects.

3. **Concurrent List**: The Concurrent List consists of subjects on which both the central government and the state governments have the authority to make laws. Some examples of subjects under the Concurrent List include criminal law, bankruptcy and insolvency, marriage and divorce, education, etc. Both the central and state governments can make laws on these subjects, but in case of a conflict, the central law prevails.

Economic and social planning falls under the Concurrent List. This means that both the central government and the state governments have the power to make laws related to economic and social planning. However, in case of any inconsistency between the central and state laws, the central law takes precedence.

The inclusion of economic and social planning in the Concurrent List reflects the importance of collaboration and coordination between the central and state governments in formulating policies and plans for the overall development of the country. It allows for a shared responsibility and ensures that the interests of both the central and state governments are taken into account while formulating and implementing economic and social plans.

Therefore, economic and social planning comes under the Concurrent List in the Indian Constitution.