Which of the following is FALSE? Select one:

a. An increase in the tax rate on firms revenues will cause the equilibrium real interest rate to rise.

b. According to Tobins q theory of investment, a decline of stock prices will cause the capitals market value of a firm to fall.

c. Desired national saving is the level of national saving that occurs when consumption is at its desired level.

d. For a borrower, both the substitution and income effects of a higher real interest rate act to increase saving.