Which statement about Bluetooth is true?

• A. It uses copper cables to transfer data
• B. It requires a direct line-of-sight for all connections
• C. It operates over several kilometres
• D. It is found in many different devices

Answer: (D)

Bluetooth is a short-range wireless technology used to connect devices for exchanging data and audio. Because it’s designed for low power and close distances, it’s included in a wide range of devices—from phones and headphones to speakers, computers, wearables, and many IoT gadgets. This ubiquity is why the statement about being found in many different devices is true. The other ideas don’t fit: Bluetooth uses radio waves, not copper cables, so data transfer doesn’t require physical wires. It doesn’t need direct line-of-sight; signals can pass through obstacles, though walls can affect performance. And its range is limited to short distances—usually up to about 10 meters for common devices, with some versions reaching around 100 meters—not kilometres.