The correct answer is **C chloroplasts**. Photosynthesis is the process by which plants use sunlight, water, and carbon dioxide to create oxygen and energy in the form of sugar. Photosynthesis occurs primarily in chloroplasts, which are organelles that contain chlorophyll, a pigment that absorbs light and converts it into chemical energy. Chloroplasts are most abundant in leaf cells, where they capture light energy and use it to synthesize organic compounds.