Volume? Is that what you mean?
 
        
             
        
        
        
During the S phase in the cell cycle, the chromosomes are replicated so that there are two copies. These copies are necessary so that each daughter cell created during the M phase will have an identical copy of the DNA.
Therefore, the answer is A: The DNA must be replicated. 
The chromosomes joining, cell membrane expanding, and cytoplasm separating all happen during the M phase (mitosis).
        
             
        
        
        
<span>It is usually the best practice to start checking from his or her lower limbs, toes and gradually progress upwards ,legs waist , stomach, chest, hands and the head lastly. In short, do it from the bottom to the top.</span>