What characteristic defines a high CRI fluorescent lamp?

A high Color Rendering Index (CRI) fluorescent lamp is characterized primarily by its ability to accurately reproduce colors in comparison to natural light. High CRI values, typically above 90, indicate that the lamp can render colors more faithfully, which is crucial in applications where color discrimination is important, such as in art studios, retail environments, or anywhere accurate color perception is necessary.

Consistency in color temperature means that the light emitted from the lamp appears stable and does not fluctuate in color, which supports the accurate perception of colors and visual comfort. Therefore, this characteristic is integral to high CRI fluorescent lamps, making option A the correct choice.

Other options do not primarily relate to the defining feature of CRI. For instance, suitability for outdoor use does not necessarily correlate with color rendering capabilities, and while efficiency is important, it is measured by lumens per watt and does not directly indicate color rendering performance. Additionally, dimming ability pertains to the lamp's controllability and does not define how well the lamp can render colors.