Sugar-phosphates and nucleotides
        
             
        
        
        
Answer:
The correct answer is C. differentiation. 
Explanation:
Cell differentiation is a process via which generic embryonic cells are transformed into specialized cells through a process of gene expression. Certain signals from inside and outside our body initiates gene expression. 
Cell differentiation occurs at various stages of development, which causes the size and the shape of the cell to change dramatically. 
Importance of cell differentiation:
- Plays vital role in embryonic development
- Helps in developing organisms throughout their life
 
        
             
        
        
        
Scientists prove their hypothesis is true about Scientists can never "prove" their hypotheses are true, because some future experiment, possibly using new technology not currently available, might show the hypothesis to be false after all.