Why are NVGs generally not effective during the daytime?

Night Vision Goggles (NVGs) are primarily designed to amplify the very low levels of ambient light, such as moonlight or starlight, to provide visibility in darkness. During the daytime, natural sunlight saturates the sensors, overwhelming the NVGs. This saturation can lead not only to a reduction in the effectiveness of the goggles but also to potential damage to the internal components, as they are not built to handle such intensities of light.

The design and function of NVGs focus specifically on enhancing low-light environments. While there are certain technologies that can operate in varying light conditions, NVGs are limited by their need for minimal light to function effectively. The potential for damage from bright light sources makes their use during daylight hours inappropriate and unsafe. Thus, option B accurately captures the reasoning behind the ineffectiveness of NVGs in daylight and highlights a critical aspect of their operational limitations.