I am pretty sure the awnser is B the collapse of communism 
 
        
             
        
        
        
The answer is B because the trees would help hold the soil in place helping to prevent erosion
 
        
                    
             
        
        
        
It's either Dearing or Independence.
        
             
        
        
        
Answer:
C. to serve in the military
Explanation:
It is not a obligation of citizens. Hope this helps! Please mark as brainiest!