They classify on how they reproduce.
<span>C. Cells, Tissues, Organs, Organ Systems
The answer is C. Cells are the fundamental unit of life. Without them, life would not possibly exist. Well that is according to the cell theory, which states that cells are the basic unit of life, cells came from pre-existing cells and cells make up living organisms.
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ANSWER:
I think it's the second one.
EXPLANATION:
in primary succession newly exposed or newly formed rock is colonized by living things for the first time. in secondary succession an area that was previously occupied by living things is disturbed, then recolonizeed following the disturbance.