Explanation:

The National Development Council (NDC) was a body that included:

• Prime Minister of India
• Union Cabinet Ministers
• Chief Ministers of all States
• Members of the Planning Commission
• And Administrators of Union Territories

It was established in 1952 with the purpose of:

• Strengthening and mobilizing the effort and resources of the nation
• Promoting common economic policies
• Ensuring balanced and rapid development of all parts of the country

Although the Planning Commission has been replaced by NITI Aayog, the NDC was not formally abolished but became inactive after 2015.

Other Options:

• (A) Planning Commission – An executive body, not composed of all these members.
• (C) Zonal Council – Includes only specific state representatives and Union Home Minister.
• (D) Regional Council – No such constitutional or significant administrative body in this context.

Conclusion:

The Prime Minister, Union Cabinet Ministers, Chief Ministers, and Council of Ministers were all part of the National Development Council.
Hence, the correct answer is (B) National Development Council.