Which of the following statements is CORRECT? a. The stock valuation model, P0=D1/(fssg), can be used to value firms whose dividends are expected to decline at a constant rate, ie, to grow at a negative rate, b. If a stock has a required rate of teturn rs=12% and its dividend is expected to grow at a constant rate of 5%, this implies that the stock's dividend yieid is also 5% c. The constant growth model cannot be used for a zero growth stock, where the dividend is expected to remain constant over time. d. The price of a stock is the present value of all expected future dividends, discounted at the dividend growth rate. e. The constant growth model is often appropriate for evaluating start-up companies that do not have a stable history of growth but are expected to reach stable growth within the next few years