"Watermelon snow" in Antarctica is caused by a species of photosynthetic green algae that thrives in subzero temperatures (Chlamydomonas nivalis). These algae are also found in high altitude in year-round snowfields. In both locations, UV light levels tend to be high. The reddish-pink color of these algae is due to the presence of carotenoid pigments, which absorb blue light while reflecting red light. Those pigments protect the chloroplast from ultraviolet radiation, as well as absorbing heat, which provides the algae with liquid water as the snow melts around it. This molecular variation in plants illustrates A. relative fitness because the molecular adaptations in chlorophyll pigments have passed to the next generation
B. innate variability because plants have evolved molecular differences to an environmental stimuli
C. unselective adaptation because plants have evolved molecular differences to adapt to different wavelengths of light
D. inclusive fitness because differences in chlorophyll pigments increase the proliferation of beneficial traits in the population