Final answer:
Red light absorbed by chlorophylls has the longest wavelength in the visual spectrum, and therefore has lower energy than light of shorter wavelengths like blue or violet.
Step-by-step explanation:
The characteristics of red light absorbed by chlorophylls in photosynthesis are significant for understanding how plants use light energy. The correct characteristic of red light, which refers to part of the visible light spectrum utilized by chlorophyll for photosynthesis, is that its photons have the longest wavelength in the visible spectrum. This means that photons of red light have lower energy compared to other colors in the visible spectrum, such as blue or violet, which have shorter wavelengths and higher energy. Therefore, the correct answer to the student's question is C. Its photons have the longest wavelength in the visual spectrum, which means they carry the least amount of energy compared to other colors of visible light.