问题如下：
Other things equal, equilibrium price-to-earnings (P/E) ratios will most likely decrease if:
选项：
A.real interest rates decrease.
B.inflation is expected to increase.
C.there is less uncertainty about future inflation.
解释：
B is correct.
Other things being equal, an increase in inflation expectations would result in lower equity prices relative to current earnings. This would result in lower equilibrium P/E ratios.
考点：equity risk premium
解析：
A, 影响P/E中的P。P可以通过未来现金流折现求和计算， real interest rates 的减小使得分母折现率减小，因此P变大，P/E变大。
B，与A同理，影响分母折现率，因此P变小，P/E变小。
C，影响分母折现率，因此P变大，P/E变大。
C和 expected inflation这部分不确定的补偿是一个意思吗？
