Answer:
B. Constants
Explanation:
Constants are the factors that stay the same throughout the entire experiment no matter which group. The definition of a constant is "a situation or state of affairs that does not change." this furthers the point that constant is the correct answer because they don't change in the experiment.
 
        
                    
             
        
        
        
<span>Evolution of birds is result of a drastic change in how dinosaurs evolved. </span>
        
             
        
        
        
Is there more for the question? Just because it has the prices there is still nothing about the amount.
        
             
        
        
        
Yes, DNA synthesis is a part of creating DNA.
        
                    
             
        
        
        
Answer:
neither
Explanation:
because humans are the ones that make energy available for cell activity