Because around the world we dont all speak the same so by using these names we know we are talking about the same animals.
        
             
        
        
        
I believe the answer is A hope this helps :)
        
                    
             
        
        
        
Diffusion is the spontaneous movement of substances from a region of high concentration to a region of low concentration.
Osmosis is the passage of water molecules from a high water concentration region through a selectively permeable membrane to a low water concentration region.
In diffusion, selectively permeable membrane is neither required nor involved while in osmosis, it is involved.
 
        
             
        
        
        
P waves do not move through liquid material
        
             
        
        
        
Moment magnitude estimates the amount of energy an earthquake releases and is derived from the amount of displacement along FAULT.