i would say that your answer would be confidence 
 
        
                    
             
        
        
        
C.3 vaccines help prevent diseases and stuff
 
        
                    
             
        
        
        
Explanation:
If I'm correct, mental health and physical health go hand in hand, if you are healthy mentally. Meaning, you're happy, not depressed and know how to take care of yourself mentally you are more likely to be health physically because you will have more motivation to keep yourself healthy, this also helps with self-esteem due to the fact, being mentally healthy means you have a good balance of self-esteem because you will understand mentally that a healthy balance of self-esteem will make your mind naturally want to be healthy physically and be mentally healthy as well.  I hope this makes sense, if not tell me and I will simplify or explain a little better.
 
        
             
        
        
        
True, Following the 8x8 rule is recommended in living a healthy life.