Ferns are pointy and mosses is not!
        
             
        
        
        
Answer: Commensalism
Explanation: Well you can already eliminate parasitism because that is when an organism leeches off another. Mutualism is when one organism needs to depend on another compared to A where both are benefited.  Then you can eliminate d because competition is when two organism compete with each other for survival not benefiting them both. 
 
        
             
        
        
        
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