A Large Open Economy Has Desired National Saving of S^d

Multiple Choice

A large open economy has desired national saving of S^d = 1200 + 1000r^w,and desired national investment of I^d = 1000 - 500r^w.The foreign economy has desired national saving of = 1300 + 1000r^w,and desired national investment of = 1800 - 500 r^w.The equilibrium world real interest rate equals

A) 0.05.
B) 0.10.
C) 0.15.
D) 0.20.