Final answer:
Chlorophyll a absorbs blue and red light, and chlorophyll b absorbs blue and red-orange light; both reflect green light, which is why plants appear green.
Step-by-step explanation:
The difference between chlorophyll a and chlorophyll b in terms of light absorption is significant in their roles in photosynthesis. Option A) is correct: chlorophyll a absorbs blue and red light, while chlorophyll b helps extend the range of light that can be used in photosynthesis by absorbing different wavelengths, specifically blue and red-orange light. Neither pigment absorbs green light; rather, they both reflect it, which is why plants appear green.