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

The Reserve Bank of India encouraged the setting up of National Payments Corporation of India (NPCI) to act as an umbrella organisation for operating various Retail Payment Systems (RPS) in India. NPCI became functional in early 2009. NPCI has taken over the National Financial Switch (NFS) from the Institute for Development and Research in Banking Technology (IDRBT).  National Payments Corporation of India links all the ATMs in India. It is expected to bring greater efficiency by way of uniformity and standardization in retail payments and expanding and extending the reach of both existing and innovative payment products for greater customer convenience.