Final answer:
Chlorophyll is the pigment that absorbs light energy in photosynthesis, particularly absorbing red and blue wavelengths of light and reflecting green, while carotenoids would be least affected if only green light was absorbed.
Step-by-step explanation:
The pigment that absorbs light energy (photons) in photosynthesis is chlorophyll. This is a light-harvesting pigment molecule that plays a crucial role in the light-dependent reactions of photosynthesis by absorbing the energy from sunlight. In particular, chlorophyll a is the most common and abundant pigment, absorbing primarily red and blue wavelengths and reflecting green, which is why plants appear green. Carotenoids are another type of pigment that absorb in the blue region of the spectrum and reflect yellow, red, and orange wavelengths. If the absorption spectrum of photosynthetic pigments was restricted to the green portion of the spectrum, carotenoids would be affected the least because they absorb wavelengths outside of the green region.