Answer:
3
Step-by-step explanation:
Infrared, is much more different compared to Bluetooth and WiFi. Infrared uses, as the name infers… the infrared spectrum of light. It is basically red light which is not visible to our human eyes. Unlike radio waves, infrared cannot pass through walls and other obstructions, so the applications are usually limited to devices that are within Line-Of-Sight or where light can travel