问题如下：
With respect to their discussion of yield curves, Tyo and her assistant are most likely discussing which term structure theory?
选项：
A. Pure expectations theory
B. Local expectations theory
C. Liquidity preference theory
解释：
C is correct.
Liquidity preference theory suggests that liquidity premiums exist to compensate investors for the added interest rate risk that they face when lending long term and that these premiums increase with maturity. Tyo and her assistant are assuming that liquidity premiums exist.
为什么这题不能是local expectation theory？
