The correct answer is: A. J. M. Keynes.
The Imperial Bank of India was established on 27 January 1921, by the merger of the Imperial Bank of India and the three Presidency Banks of Bengal, Bombay, and Madras. The bank was established on the advice of J. M. Keynes, who was then a member of the British Treasury. Keynes believed that the merger would create a stronger and more efficient bank that would be better able to serve the needs of the Indian economy.
Lord Illingworth was a British politician who served as Chancellor of the Exchequer from 1908 to 1911. He was not involved in the establishment of the Imperial Bank of India.
King George V was the King of the United Kingdom and the Dominions of the British Commonwealth from 1910 until his death in 1936. He was not involved in the establishment of the Imperial Bank of India.
Winston Churchill was a British statesman who served as Prime Minister of the United Kingdom from 1940 to 1945 and again from 1951 to 1955. He was not involved in the establishment of the Imperial Bank of India.