What type of polarization is commonly used for VHF and UHF transmissions?

The correct type of polarization commonly used for VHF and UHF transmissions is horizontal polarization. This is particularly effective for line-of-sight communications in these frequency ranges, where wavelengths can be affected significantly by physical obstructions and reflections.

Horizontal polarization allows signals to propagate more effectively over the horizon and maintains a clearer line of sight, which is advantageous in many terrestrial and space communications scenarios at these frequencies. It's worth noting that while other forms of polarization, such as vertical and circular, have their specific applications, horizontal polarization remains the standard due to its effectiveness in minimizing multipath interference and optimizing reception in various environments.