Which of the following is a most likely consequence of implementing the 'Unified Payments Interface (UPI)'?

1. A

   Mobile wallets will not be necessary for online payments.

   (a) Mobile wallets will not be necessary for online payments. UPI lets a customer pay from a bank account via a virtual address or QR without keeping a closed-loop wallet balance. That is the most direct consequence and the official key.

2. B

   Digital currency will totally replace the physical currency in about two decades.

   (b) Digital currency will totally replace physical currency in about two decades. UPI does not imply a timed end of cash. Not the key.

3. C

   FDI inflows will drastically increase.

   (c) FDI inflows will drastically increase. UPI is a domestic payments rail, not an FDI magnet by itself. Not the key.

4. D

   Direct transfer of subsidies to poor people will become very effective.

   (d) Direct transfer of subsidies will become very effective. DBT uses bank accounts and Aadhaar; it is not the distinctive UPI consequence. Not the key.

Summary. Official key is (a) mobile wallets will not be necessary for online payments. Unified Payments Interface, built by NPCI, moves money between bank accounts in real time using a VPA, QR or intent-flow, so a prepaid wallet is optional rather than required. It does not schedule the death of cash, guarantee FDI, or redefine DBT. IMPS and NEFT are neighbouring rails. BHIM is the government UPI app brand of that period.