science hasnt figured it out yet
 
        
                    
             
        
        
        
Answer:
b. able to travel through a vacuum.
Explanation:
The most distinguishing factor of an electromagnetic waves is that they are able to travel through a vacuum. 
These waves do not require materials in a medium for propagation. 
- Electromagnetic waves are formed by the propagation of the electric and magnetic fields. 
- They vibrate at an angle of 90° . 
- They are unlike like mechanical waves that requires that requires materials in medium for their propagation. 
 
        
             
        
        
        
Answer:
Keep going you are doing great, if you need a break go take a short walk