Answer:
ANSWER: Oxygen is a product of photosynthesis.
Explanation:
 Photosynthesis is a chemical reaction that occurs in plants.  Photosynthesis uses ATP energy from sunlight to convert Carbon Dioxide and Water into Glucose.  Oxygen is also formed during photosynthesis.  
 
        
             
        
        
        
A) weapons for an evolutionary arms race w/ disease causing organisms
        
                    
             
        
        
        
Answer is: C
Hopefully this helps you, have a nice day! :)
in addition to that; (it's pairs of 4 types of (c))