Unitary: no local decisions. 
Federal: some local decision.
Confederation: a lot of local decisions.
        
             
        
        
        
I believe it is c I researched all of them and the most convenient is gothic architecture
        
                    
             
        
        
        
Spatial perspective is to study something in terms of location, distance and direction. Meanwhile, ecological perspective is to study something in terms of environment and social interaction. Good luck! 
        
             
        
        
        
<span>What you describe is called devolution. This is when power is transferred to lower levels. When devolution occurs, autonomous regions occur and things like federations are created because numerous autonomous regions work together under federative rule, but still retain a great degree of independence.</span>
        
             
        
        
        
Trade and warfare. Trade can increase the countries wealth where war can destabilize a region leading to economic downturns.