请问为何b是对的呀？谢谢老师
问题如下图：
选项：
A. 
B. 
C. 
解释：
NO.PZ2015122801000017 问题如下 Regarng fixeincome inxes, whiof the following scriptions is least accurate ? A.There are various types in the composition of fixeincome inxes. B.It is fficult anexpensive for fixeincome portfolio managers to replicate a fixeincome inx. C.The ta of fixeincome securities are relatively easy to get because the securities are often liqui C is correct.Inx provirs must penon alers for fixeincome security prices anthe securities are illiqui So ta are relatively fficult to get.C是正确的。对于债券一类的固定收益类证券，很多债券都是公开发行后就被投资者持有不再进行交易的，所以这些债券的流动性很差，市场上很难获得这些债券的信息，所以C不正确，选C.而B是正确的，因为一方面组成指数的某些债券很少有人卖出，所以很难获得（流动性不佳，买入成本就可能非常高昂）；另一方面市场上的债券数量和类型也比股票多许多倍，一个指数内部构成的债券也会相对复杂；这些因素都会大导致基金经理复制指数变得又困难又昂贵。 请问老师，复制指数是什么意思？有哪些指数是可以复制的呢？
It is fficult anexpensive for fixeincome portfolio managers to replicate a fixeincome inx. The ta of fixeincome securities are relatively easy to get because the securities are often liqui C is correct. Inx provirs must penon alers for fixeincome security prices anthe securities are illiqui So ta are relatively fficult to get.请问老师，B怎么？为啥不选B？
