can you please explain me how to solve these questions? thanks :)

In the past many oil exporter countries run high current account surplus . Therefore, the national aggregate demand of these countries was above the national aggregate supply Therefore, these countries are lending to the rest of the world Therefore, they had at the time a scal surplus Therefore, in these countries private saving was necessarily less than private investment Suppose that suddenly people decide to save a larger proportion of their income. As a result: The equilibrium output in the short term will be higher, because there are more loanable funds for private investment The equilibrium output in the short term will be lower, because there is a negative impact on aggregate demand The equilibrium output in the short term will remain unchanged, because the prosperity to consume is constant The equilibrium output in the short term will be lower, because the money will also be lower