dependant on each other 
is it multiple choice if so what are the choices
 
        
                    
             
        
        
        
I don’t think you’re looking for a part but I believe you’re looking for blood, more specifically the red blood cells
        
                    
             
        
        
        
Antibodies, antigens are the bad things antibodies fight :)
        
             
        
        
        
Apples because it’s a fruit.
Chicken because it’s lean meat.
Salad because it’s fresh greens.
Carrot because it’s a vegetable.
Water because it has 0 calories.