For markets to be in equilibrium, that is, for there to be no strong pressure for prices to depart from their current levels,

a. The past realized rate of return must be equal to the expected future rate of return; that is, = .

b. The expected rate of return must be equal to the required rate of return; that is, = r.

c. The required rate of return must equal the past realized rate of return; that is, r = .

d. All of these statements must hold for equilibrium to exist; that is = r = .

e. None of these statements are correct.