Macroeconomics 20th Edition by Campbell McConnell,Stanley Brue,Sean Flynn

Exercise 22

In this figure, if the real interest rate falls from 6 to 4 percent:
A) investment will increase from 0 to $30 billion.
B) investment will decrease by $5 billion.
C) the expected rate of return will rise by $5 billion.
D) investment will increase from $25 billion to $30 billion.