Answer:
B. hydrogen bond
Explanation:
The double helix is held together by hydrogen bonds between the bases
 
        
             
        
        
        
Nuclear division occurs in mitosis. 
        
             
        
        
        
Answer:
it's D. I believe anyways is it if you can pick two pick A,D, or D and C who knows at this point 
sorry I'm not much help but I hope it did something