The correct answer is Option 3: World Bank.

The Ease of Doing Business Index is an annual report published by the World Bank, which measures the ease of doing business in different countries around the world. The index provides rankings based on various indicators such as starting a business, getting construction permits, getting electricity, registering property, getting credit, protecting minority investors, paying taxes, trading across borders, enforcing contracts, and resolving insolvency.

The World Bank has been publishing the Ease of Doing Business Index since 2003 as part of its efforts to promote economic growth and development by encouraging countries to adopt business-friendly policies and regulations. The index is widely used by governments, policymakers, and businesses to assess the business environment in different countries and make informed decisions on investment and trade.

Option 1: Organization for Economic Cooperation and Development (OECD) is not the correct answer as the Ease of Doing Business Index is not published by the OECD. The OECD is an international organization that promotes economic development and cooperation among its member countries, but it does not publish rankings related to the ease of doing business.

Option 2: World Economic Forum is not the correct answer either, as the Ease of Doing Business Index is not published by the World Economic Forum. The World Economic Forum is a non-profit organization that focuses on public-private cooperation and engages in research and advocacy on a wide range of economic and social issues, but it does not publish rankings related to the ease of doing business.

Option 4: World Trade Organization (WTO) is also not the correct answer, as the Ease of Doing Business Index is not published by the WTO. The WTO is an international organization that deals with the rules of trade between nations, but it does not publish rankings related to the ease of doing business.

In conclusion, the World Bank is the organization that declares the ranking of India and other countries in the Ease of Doing Business Index, as it publishes the index annually based on various indicators to assess the ease of doing business in different countries.