In which of the following places would you most likely experience the greatest level of political security? a. a multinational state b. a sovereign state c. a state that is being annexed d. a stateless nation

You would definitely not expect political stability in a state that is being annexed or which does not have a territory - rather the opposite would be true.

Both multinational and souvereign states can have a high lever of political security. However, in a multinational state one can also expect some conflicts between the different ethnic groups - therefore the best answer is "a sovereign state"