Assertion (A): Infrared (IR) is a wireless technology used for data communication.

Reasoning (R): Infrared involves the usage of electromagnetic radiation whose wavelength is shorter than the visible light but can penetrate easily through walls and obstacles; thus, it is used where there is an obstacle between two devices under communication.

1. Both A and R are true and R is the correct explanation of A.
2. Both A and R are true but R is not the correct explanation of A.
3. A is true but R is false.
4. A is false but R is true.

A is true but R is false.

Explanation
Infrared (IR) is a wireless technology used for data communication. Infrared involves the usage of electromagnetic radiation, specifically infrared light, to send data. The data is transmitted through the air and can propagate in open space; however, it cannot penetrate the walls of a room and is affected by distance, noise, and heat. It is an example of a short-range wireless network.