The range of optical communication refers to the range of electromagnetic waves that can be used for transmitting information through optical fibers. Optical communication is a method of transmitting data using light as the carrier signal. It is widely used in telecommunications, internet connectivity, and other applications that require high-speed data transmission.

The correct answer is option 'B' - Microwaves to ultraviolet. This means that the range of optical communication includes a portion of the electromagnetic spectrum that spans from microwaves to ultraviolet waves.

Explanation:

Microwaves:
- Microwaves have longer wavelengths and lower frequencies compared to visible light.
- They are commonly used for wireless communication, such as Wi-Fi and cellular networks.

Infrared:
- Infrared waves have longer wavelengths than visible light and shorter wavelengths than microwaves.
- In optical communication, infrared waves are often used for short-range communication, such as remote controls and infrared data transmission.

Visible Light:
- Visible light is the portion of the electromagnetic spectrum that is visible to the human eye.
- It has a range of wavelengths from approximately 400 to 700 nanometers.
- Optical fibers are designed to transmit visible light signals efficiently, allowing for high-speed data transmission.

Ultraviolet:
- Ultraviolet waves have shorter wavelengths and higher frequencies than visible light.
- They are often used for applications such as germicidal lamps, UV curing, and fluorescence spectroscopy.

By including microwaves to ultraviolet waves in the range of optical communication, a wide range of frequencies can be utilized for transmitting information. This allows for flexibility in choosing the appropriate wavelength for specific applications, depending on factors such as distance, data rate, and available technology.

It's important to note that the range of optical communication does not include x-rays and gamma rays. X-rays and gamma rays have much shorter wavelengths and higher frequencies than ultraviolet waves. They are typically used in medical imaging, security scanning, and industrial applications, but not for optical communication through fibers.