State A and State B share a common border. State A has ratified the UN Convention on the Prevention and Punishment of the Crime of Genocide; State B has not. State A has entered into a treaty establishing commercial relations with State X and extending Most Favored Nation status to State X; State B has not. State A has a treaty with State Y that establishes the international border between State Y and State A's Western Province. Which of these treaties will continue to have effect in the changed territory if

a. State A cedes its Western Province to State B?

b. the Western Province obtains its independence?

c. State A and State B merge and become new State C?