Concept:Photosynthesis depends on light energy, and chlorophyll is the pigment that captures it.Explanation:During photosynthesis, green plants convert carbon dioxide and water into glucose and oxygen using sunlight.Chlorophyll in the chloroplasts absorbs solar energy and makes it available for the photosynthetic reactions.Therefore, chlorophyll is necessary because it absorbs solar energy, not because it produces or absorbs gases like oxygen or carbon dioxide.Answer:B. absorbs solar energy.