I dont want to mislead you, but I believe the answer is A because letter B is wrong because plants go through cellular respiration and photosynthesis, whereas animals go through cellular respiration but not photosynthesis, and for C, I've never heard of that so it doesnt seem likely.
Erosion can be caused by water wearing down a surface
Wind constantly or midly knocking or hitting a surface making it erode
Any natural form of life
rain/condensation/precipitation
something like that
