老师麻烦帮忙理解下这道题

问题如下：

Based on the Grinold–Kroner model, which of the following factors is the primary channel through which economic growth can impact equity returns?

选项：

A.Dividend yield B.Earnings growth per share C.Expected repricing term of the market's P/E ratio

解释：

A Incorrect because over time, the dividend yield, dy, has been found to be fairly stable and a significant contributor to equity market returns. However earnings growth per share is the primary channel through which economic growth can impact equity returns.

B Correct because earnings growth per share is the primary channel through which economic growth can impact equity returns.

C Incorrect because while there is some evidence that with increasing GDP growth rates, P/E ratios trend higher as investors perceive the country and its economy to be less risky, However, the primary impact of this repricing term is the volatility in the market’s P/E ratio over market cycles. Whereas earnings growth per share is the primary channel through which economic growth can impact equity returns.