VIEW ANSWER FOR PART FOUR : The Income Adjustment Mechanism and Synthesis of Automatic Adjustments

a. when there are no foreign repercussions

b. with foreign repercussions for an autonomous increase in nation 1's X that replace domestic production in nation 2

*c. with foreign repercussions for an autonomous increase in I in nation 1

d. with foreign repercussions for an autonomous increase in I in nation 2