Cinnamomum cassia belongs to angiosperms, and the energy converters in cells are chloroplasts and mitochondria. Chlorophyll in chloroplasts can absorb light energy, convert it into chemical energy, and store it in the organic matter it produces. Mitochondria can decompose organic matter in cells into carbon dioxide and water with the participation of oxygen, and at the same time release chemical energy in organic matter for cells to use. Animals are heterotrophic, and their cells do not contain chloroplasts that can carry out photosynthesis, but only mitochondria. However, not all plant cells have chloroplasts, for example, the energy converter in the petal cells of osmanthus trees only has mitochondria and no chloroplasts.

So choose: B.