The delivery of a speech helps the audience understand the topic, what you're talking about, and keeps the speech on track.
For example, if you were giving a speech on Romeo and Juliet, you wouldn't want to get off topic by giving information about Shakespeare's life instead of information and analysis of the play.
        
             
        
        
        
The answer is d I believe 
All of the above
        
                    
             
        
        
        
B because it gives a commentary view on the situation