The correct answer is National Payments Corporation of India. National Payments Corporation of India (NPCI) is the apex authority for maintaining a nationwide link of all the ATMs in India. The NPCI was founded on 2008 for the operation of retail payments in India. NPCI exercises this role through its wing IDRBT (Institute for Development of Research in Banking Technology). IDRBT created a massive network called National Financial Switch in the year 2004 for linking all the ATMs in India. The NPCI provides a variety of services those are Rupay: A domestic card scheme, BHIM: Unified payment interface, Check truncation system and Aadhar enabled payment system. Additional InformationIndian Bank Association (IBA) is formed in 1946. It is a representative body of management of banking in India. IBA was formed for development, coordination and strengthening of Indian banking, and assist the member banks in various ways. National Securities Depository Limited (NSDL) is a financial organization created to hold securities such as bonds, shares etc. in the form of physical or non-physical certificates i. e. in dematerialized format. These securities are held in depository accounts such as funds held in bank accounts. NSDL is one of the largest Depositories in the World. It was established in August 1996. It has established a state-of-the-art infrastructure that handles most of the securities held and settled in dematerialized form in the Indian capital market. The Reserve Bank of India (RBI) is the central bank of India whose primary function is to manage and govern the financial system of the country. RBI was established on 1 April 1935 in accordance with the provisions of the Reserve Bank of India Act, 1934. The Central Office of the RBI was initially established in Kolkata but was permanently moved to Mumbai in 1937.