问题如下：
Matt has evaluating the value of Company M of $20 per share by using the H-model. The company has paid a dividend of $1 per share for the most recent year. The growth rate will decline linearly from 10% to 6% over the first four years. The dividend growth rate thereafter would be 6% per year into the indefinite future. What`s the required rate of return in his model?
选项：
A. 5.7%
B. 12.1%
C. 11.7%
解释：
C is correct.
考点：H-model
解析：根据公式：r = (D0/P0) [(1+gL) + H*(gS-gL)] + gL
将D0 = 1, P0 = 20, gs = 10%, gL = 6%, H = 4/2 = 2代入
可得r = 11.7%
我怎么算出来是6.7%?