干线子系统也可称为( )。

A．垂直子系统

B．水平子系统

C．平行子系统

D．交错子系统

Which of the following limits the ability of arbitrage to correct anomalies（）

A. Arbitrage is a relatively riskless activity, which has led to consistently reduced profits for many arbitrageurs, thereby reducing their interest in correcting market anomalies. 

B. There is no guarantee that even correctly identified relative mispricing of similar stocks will be corrected in the near term.

C. Arbitrageurs are sophisticated traders but their short supply precludes the correction of market anomalies.