The correct answer is: A lichen.
A lichen is another example of symbiotic relationship between fungi and a plant. The lichen absorbs water and nutrients from the environment and supplies them to the plant. On the other hand, the plant photosynthesizes and provides energy for the lichen. This is an example of a mutual or a symbiotic relationship where two organisms benefit each other.
Attached is a picture of a lichen that grows on a tree.