The right choice would be A
        
             
        
        
        
Answer:
the size of something from one end to the other; how long something is
-  Running race track
- tree 
 
        
                    
             
        
        
        
Answer:
The photon is a type of elementary particle. It is the quantum of the electromagnetic field including electromagnetic radiation such as light and radio waves, and the force carrier for the electromagnetic force.
Explanation:
I had a dictionary handy by me.