OK so I believe the answer will be B. because they never really give you all the information but they will give you the core info.
        
                    
             
        
        
        
I think it is C. Spinal cord controls the nerve impulses
        
             
        
        
        
Answer:
so that you can find a match for their blood type. 
Explanation:
Certain blood types don't react well with others and cause their immune system to attack, while other blood types react fine with a certain one. Group o+, for example, can donate to any + blood type.