I would go for D or A! :)
        
             
        
        
        
Because people had as pets when they got to big they let them into the wild and they came a different place 
        
             
        
        
        
The human body is made up of 11 systems of organs. 
The systems are: Circulatory, respiratory, digestive, excretory, nervous, endocrine, immune, integumentary, skeletal, muscle, and reproductive. 
 
        
                    
             
        
        
        
D. Same as the number of adenines
Thymine and Adenine will always pair together
:)