The answer is tides. 
Explanation: high tides and low tides are caused by the moon. The moons gravitational pull generates the tidal force
        
             
        
        
        
Due to brainly not accepting my essay, I have instead included a image of it. :D
 
        
             
        
        
        
B, because it's not an advantage for something to be expensive and time consuming
        
                    
             
        
        
        
Answer:
I have been to get a 
Explanation:
I c have a true conclusion for my head but I think it is a good way for me to get