Final answer:
Plants, animals, fungi, and bacteria all use cellular respiration.
Step-by-step explanation:
Plants, animals, fungi, and bacteria all use cellular respiration to derive energy from organic molecules produced by photosynthesis.
Plants, like oak trees, use energy from sunlight to produce sugar and other organic molecules through photosynthesis. Both plants and animals, such as squirrels, perform cellular respiration to release energy from the organic molecules produced by plants.
Therefore, the correct answer is A) Plants, as they are one of the organisms that use cellular respiration.