While the seed is germinating, it uses the stored starch in the cotyledons as a source of energy, but with time, the stored reserve is depleted. After the starch supply in the seed is gone, the plant still continues growing because it contain chloroplasts. The chloroplasts are a type of plastids and are a site for photosynthesis. The light energy from the sun is converted into chemical energy in the chloroplasts, which help the plant to continue growing.
Hence, the correct answer is option (c) - 'have chloroplast and use light energy to make more food'.