问题如下：
8. Based on Exhibit 4 and Intern 1’s analysis, Xavier Corporation’s sustainable dividend payout ratio is closest to:
选项：
A. 43.4%.
B. 44.6%.
C. 56.6%.
解释：
C is correct because it is based on the sustainable growth rate and the required rate of return:
Sustainable growth rate = (b in mature phase) × (Return on equity)
= (1 – Dividend payout) × (Return on equity)
0.036 = (1 – Dividend payout) × 0.083
Solving for the dividend payout ratio, the dividend payout = 56.627% ≈ 56.6%.
看了之前老师的解释，没有看懂，想再问一下为啥不能用Re=D/P+g的公式反推dividend payout ratio？