18. Under the constant growth model, if a stock's dividend is expected to grow at a constant rate of 5% a year, which of the following statements is correct? a. The expected return on the stock is 5% a year. b. The stock's dividend yield is 5% C. The stock's price one year from now is expected to be 5% higher d. The stock's required return must be equal to or less than 5%. e. The price of the stock is expected to decline in the future