Answer:
A. oak tree
Explanation:
A producer is an organism that produces or creates its own food through the process of photosynthesis. Certain organisms, like plants, algae and some bacteria undergo this process. Carbon dioxide, water, and light energy from the sun are turned into glucose and oxygen. The glucose becomes the food for the organism.
A mountain lion and a butterfly are both animals. A mushroom is a fungus. Therefore, the correct answer must be A. oak tree.
