For a stock to be in equilibrium, that is, for there to be no long-term pressure for its price to depart from its current level, then a. the expected return must be equal to both the required future return and the past realized return. b. the expected future return must be less than the most recent past realized return. c. the expected future returns must be equal to the required return. d. the required return must equal the realized return in all periods. e. the past realized return must be equal to the expected return during the same period