**Answer:**

The correct answer is option 'A', the United States of America.

**Explanation:**

The President of the United States has the authority to nominate the President of the World Bank. The World Bank is an international financial institution that provides loans and grants to the governments of poorer countries for the purpose of pursuing capital projects. It is composed of two institutions: the International Bank for Reconstruction and Development (IBRD) and the International Development Association (IDA).

The World Bank plays a crucial role in the global economy, providing financial assistance and expertise to help countries develop their economies and reduce poverty. As such, the selection of its President is a significant decision that involves careful consideration of the candidate's qualifications and experience.

In this case, Mr. Ajay Banga, an Indian-American business executive, was nominated by the President of the United States to lead the World Bank. Mr. Banga is the former CEO of Mastercard and a respected figure in the business world. His nomination demonstrates the United States' confidence in his ability to effectively lead the World Bank and contribute to its mission of promoting economic development and poverty reduction.

It is worth noting that the nomination of the World Bank President is subject to approval by the World Bank's Board of Executive Directors, which is composed of representatives from its member countries. The Board evaluates the qualifications and suitability of the nominee before making a final decision.

In conclusion, the President of the United States nominated Mr. Ajay Banga to lead the World Bank, highlighting his credentials and expertise in the field of finance and development.