题目内容：
根据听到的材料，回答题
What is the most fundamental difference between plants and animals?
[ A ] Plants produce their own food but animals don't.
[ B ] Plant cells have a wall which is non-living in chemical nature but animal ceils haven't.
[ C ] Plants are green but animals aren't.
[ D ] Plants can't move but animals can.
参考答案：
答案解析：