Answer:
C. A hillside that has been cleared by a volcanic eruption.
Explanation:
Pioneer species are hardy species which are the first to colonize barren environments or previously biodiverse steady-state ecosystems that have been disrupted, such as by fire or other natural disasters. Some lichens grow on rocks without soil, so may be among the first of life forms, and break down the rocks into soil for plants.
Hope this helps!
The first one with the boxing crab and anemone is mutualism.
The second one with the dog and flea is parasitism.
Answer:
I believe it is cellulose, I'm not a 100% sure