How do plants capture light energy?

Plants capture light energy primarily through pigments in the chloroplasts, specifically chlorophyll, which is the most important pigment in photosynthesis. Chlorophyll absorbs light most efficiently in the blue and red wavelengths while reflecting green light, which is why plants appear green. This absorbed light energy is then converted into chemical energy during the photosynthetic process.

While roots, stems, and cell membranes play important roles in a plant's overall function and structural integrity, they are not responsible for capturing light energy. Roots primarily absorb water and nutrients from the soil, stems support the plant and transport fluids, and cell membranes maintain the integrity of cells and regulate the movement of substances. Thus, it is the pigments within chloroplasts that are crucial for the initial step of capturing solar energy, making this the correct answer.