64.
The answer is: B
Explanation
The correct option is B: National Payments Corporation of India (NPCI).
The Unified Payments Interface (UPI) system was developed by the National Payments Corporation of India (NPCI). NPCI is an umbrella organization for operating retail payments and settlement systems in India. UPI is a real-time payment system that enables instant money transfers between bank accounts using a mobile device. It has revolutionized digital payments in India by providing a seamless and secure platform for transactions.