Answer:
A. It uses the animal’s cellular machinery to reproduce inside the animal.
Explanation:
I would go with A because since it is a virus it cannot live outside the body and thus needs to rely on host's cell for metabolism as viruses are not capable of having their own metabolism. 
 
        
             
        
        
        
Answer:
Answer is C. Modern irrigation. 
Explanation:
The word 'irrigation ' means the process of supplying water or watering of land in preparation for planting and watering of planted crops to survive. 
Modern irrigation involves the construction of hoses, channels and canals. This is done so that water will be available through out the seasons for the crops, and water will be supplied to areas where there is scarcity of water. 
Irrigation is very important because it prevents famine, improves water condition in the soil by dissolving nutrients for plant use. 
 
        
             
        
        
        
The answer would be D. hormones, because that is the only thing not studied during cognitive psychology, which is the study of your brain and how it perceives things, how good your memory is, and how your language is
        
                    
             
        
        
        
Also is this a project or something?