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

1. The question asks which entity links all the ATMs in India. 2. The National Financial Switch (NFS) is the network that connects most ATMs across India, facilitating interoperability. 3. This network is operated by the National Payments Corporation of India (NPCI). NPCI took over the operations of NFS from the Institute for Development and Research in Banking Technology (IDRBT) in 2009. 4. The Indian Banks' Association (IBA) is an association of banks and does not operate the ATM network. 5. The National Securities Depository Limited (NSDL) deals with securities. 6. The Reserve Bank of India (RBI) is the central bank and regulator, but NPCI is the entity that manages the interbank ATM network.