The answer is C. Military service (-:
        
                    
             
        
        
        
Answer:
Giving the Union control of the Mississippi River
Explanation:
The Union wanted control of the Mississippi to cut off trade and transport for the South. The river being taken also made things harder for the Confederates (because it cut their side in half, so the Union had the upper hand).
 
        
             
        
        
        
Germany failed to take over Europe
Italy failed to gain land in Europe
Austria-Hungary failed to keep stable, now they don't exist.
Bulgaria failed to gain the land they wanted
Turkey failed to get back at Russia for the *Crimean Wars
*could be a different war not sure