Explanation:

- Option 1: National Statistical Office (NSO):

- Responsible for statistical data collection and analysis, like surveys on the economy.

- Does not involve planning or policy-making roles.

- Option 2: Centre for Monitoring Indian Economy (CMIE):

- A private organization providing economic and business databases.

- Not a government planning body.

- Option 3: Central Statistical Organisation (CSO):

- Merged into NSO for statistical operations.

- Focuses on data rather than planning.

- Option 4: NITI Aayog:

- Replaced the Planning Commission in 2015.

- Focuses on sustainable development and cooperative federalism.

Correct Answer: NITI Aayog