Why do plants exhibit a green color?

Plants exhibit a green color because they reflect the color green. This phenomenon occurs primarily due to the presence of chlorophyll, the key pigment involved in photosynthesis. Chlorophyll absorbs light most efficiently in the blue and red wavelengths but reflects green wavelengths, which is why we perceive plants as green.

The absorption spectrum of chlorophyll indicates that it is not effective at utilizing green light for photosynthesis. Instead, this reflected light is what contributes to the plant's visible green hue. While chlorophyll is indeed pivotal for the process of photosynthesis and plays a role in the overall health and functionality of plants, the specific reason for their green color lies in their reflection of light rather than absorption.

In contrast, other options may suggest different aspects of plant coloration or functions that do not accurately explain the visible green appearance of plants. Some may imply that plants produce only green pigments or that oxygen generated in the photosynthesis process changes the color—which is not how color perception works in this context. Therefore, the reflection of green light is the primary reason for the green color of plants.