B is the correct answer. Other options may look alike. However for a state to be recognized it must have option B’s attributes. For instance option A only explained the presence of a government, police, army , navy and air force but no population, no sovereignty and no territory. So that’s incomplete. Option C only explain two tiers of government. These are not enough adjectives to describe a state. Option D is equally wrong because: It had no government, sovereignty, population and territory.