Wireless transmission refers to the process of transmitting information or data from one device to another without the use of physical cables or wires. It utilizes electromagnetic waves to carry and deliver the information. There are several methods of wireless transmission, and radio waves, microwaves, and infrared are all commonly used for this purpose.

Radio Waves:
- Radio waves are a type of electromagnetic radiation with long wavelengths, ranging from a few millimeters to several kilometers.
- They are commonly used for wireless communication, including broadcasting radio and television signals, as well as for mobile phones, Wi-Fi, and Bluetooth.
- Radio waves can travel long distances and penetrate through obstacles, making them suitable for long-range communication.

Microwaves:
- Microwaves have shorter wavelengths than radio waves, typically ranging from one millimeter to one meter.
- They are commonly used for wireless communication, such as satellite communication, microwave ovens, and radar systems.
- Microwaves can carry large amounts of data and have higher bandwidth compared to radio waves, making them suitable for high-speed communication.

Infrared:
- Infrared radiation has even shorter wavelengths than microwaves, ranging from 0.75 to 1000 micrometers.
- It is commonly used for short-range communication, such as remote controls, infrared data transmission, and infrared sensors.
- Infrared signals are typically used for line-of-sight communication, meaning that there should be a direct path between the transmitter and receiver.

All of the mentioned:
- The correct answer to the question is option 'D', which states that wireless transmission can be done via radio waves, microwaves, and infrared.
- This means that all three methods mentioned above are used for wireless communication, depending on the specific application and requirements.
- Each method has its advantages and limitations, and the choice of which method to use depends on factors such as range, bandwidth, data capacity, and line-of-sight requirements.

In conclusion, wireless transmission can be accomplished through radio waves, microwaves, and infrared. Each method has its own characteristics and applications, and the choice of method depends on the specific requirements of the communication system.