Which one of the following links all the ATMs in India?

The correct answer is C) National Payments Corporation of India (NPCI). NPCI is the umbrella body for retail payment systems, set up in 2008 by RBI and the Indian Banks' Association (IBA) and now a Section 8 company. Its National Financial Switch (NFS) is the network that routes ATM transactions between banks, which is why a card from one bank works at another bank's machine.

• A) IBA is the representative and advisory body of banks. It negotiates with the government and sets industry norms, but it does not operate any switch.
• B) NSDL is a securities depository that holds dematerialised shares and bonds. It has nothing to do with ATM networks.
• D) RBI regulates and oversees payment systems under the Payment and Settlement Systems Act, 2007. It is the regulator, not the operator of the interbank ATM switch.

The core concept is payment system infrastructure: regulator, operator and industry body are three separate roles. This links to GS-III (indian economy, digital payments and financial inclusion), and NPCI's role in UPI, RuPay and IMPS is a frequent Mains theme.

Trap: aspirants pick RBI because it is the apex bank and regulator. Ask who runs the switch, not who regulates it.