NO.PZ202112010200000104
问题如下：
In her market research, the manager learns that ASX 3-year and 10-year Treasury bond futures are the most liquid products for investors trading and hedging medium- to long-term Australian dollar (AUD) interest rates.
Although neither contract matches the exact characteristics of the cash bonds of her choice, which of the following additions to a barbell portfolio best positions her to gain under a bull flattening scenario?
选项：
A.Purchase a 3-year Treasury bond future matching the
money duration of the short-term (2-year) position.
Sell a 3-year Treasury bond future matching the money duration of the short-term bond position.
Purchase a 10-year Treasury bond future matching the money duration of the long-term bond position.
解释：
C is correct.
A bull flattening is a decrease in the yield spread between long and short-term maturities driven by lower long-term yields-to-maturity.
Both A and B involve changes in portfolio exposure to short-term rates, while C increases the portfolio exposure to long-term rates to benefit from a fall in long-term yields-to-maturity.
请问这道题选B为什么不可以？在bull flattening情况下，市场好利率上升，债券价格下降，flattening说明短期价格下降更快，所以short 3年短期债券，这样理解为啥不对？谢谢
