Answer:
A decomposer is found at the end of a food chain. 
 
        
                    
             
        
        
        
The answer is A. Sound can travel through matter (solids, liquids, and gases). Sound travels faster in solids, then slower in liquids and slowest in the air. When the person in the next room makes noise, the sound travels through the air in their room, through the solid wall and in the air in your room and into your ear.
 
        
                    
             
        
        
        
All of these things are caused by Genes, so your answer is A. When two reproductive cells fuse, their traits are either dominant, or recessive. Dominant traits are displayed.