RFID technology uses radio frequencies to track objects and often features one-way communication.

• A. Bluetooth
• B. RFID (Radio Frequency Identification)
• C. GPS
• D. NFC

Answer: (B)

Identifying and tracking objects with radio-frequency tags is what RFID is all about. RFID uses a reader to emit radio waves that energize a tag attached to an object; the tag then responds with its stored identifier, allowing automated identification and inventory tracking without direct line-of-sight. Many tags are passive, meaning they don’t generate their own signal and only reply when prompted by the reader, which gives the sense of one-way communication in typical deployments. In contrast, Bluetooth is designed for two-way connections between devices, GPS relies on satellites to provide location data rather than tagging items, and NFC is a compact RFID variant that operates at very short range and often supports two-way data exchange and payments. So RFID best fits the description of using radio frequencies to track objects with common one-way reading behavior.