Which technology uses radio frequency to send transaction data over a short distance?

• A. Near Field Communication (NFC)
• B. Radio Frequency Identification (RFID)
• C. Infrared Data (IrDA)
• D. Bluetooth

Answer: (A)

The main idea here is close-range, two‑way wireless communication used for authorizing payments. Near Field Communication enables two devices to exchange data over a very short distance, typically a few centimeters, using radio frequency. This makes it ideal for contactless payments: your card or phone and the reader communicate securely to complete a transaction in seconds. NFC operates in the 13.56 MHz band and can power passive devices from the field, allowing a seamless payment experience without contact.

RFID covers a broad range of near- and far-field wireless identification, but it isn’t limited to the ultra-short range and secure, two-way payment data exchange that NFC specializes in. Infrared Data uses light rather than radio waves and requires line-of-sight, so it isn’t used for these RF-based payment transactions. Bluetooth is RF too, but it’s designed for longer-range device pairing and data transfer, not the near-field, transaction-focused use case described.