What is the most common political unit in our world today?

oligarchies
sovereign nation-states
artistocracies
single party rule

Sovereign nation-states

Explanation:

Sovereign nation-states are known to be states with population of people in which the government makes and implement laws which the citizens obey. Also, these states make decision on their own without depending on other states. Furthermore, they make laws that pertain to their foreign policy. Thus, they make social services available to their citizens such as security, infrastructures, education and so on.  

answerprimary circular reactions;