问题如下图：
选项：
A. 
B. 
C. 
解释：
我理解risk的定义是波动而不是收益的大小，B选型虽然callable的收益会低于non-callable，但是callable和putable对于投资者而言都是限定了收益和损失的上/下限，比其他类型的股票肯定是波动更小从而风险更小的不是吗
NO.PZ2015122801000030问题如下Whiof the following statements is most correct?A.When market prigoes wn, putable shares are more risky thcallable shares for investors.B.When market prigoes up, callable shares are more risky thputable shares for investors.C.When market prichanges, non-putable, non-callable shares are the most risky for investors. B is correct.When market pririses, the firm hoption to buy bathe shares , therefore investors have limitegains when they holthe callable shares. When market priops, investors csell the shares bato the firm, therefore investors have protection when they holthe putable shares.B是正确的。本题考察可卖还，可赎回股票的区别。当市场价格上升时，股票的发行方（公司）很可能会用固定价格强制买回股票，此时持有该种股票的投资者就可能无法获得股票进一步上涨的收益，面临的风险最大，所以B正确。当市场价格下降时，投资者可以强制要求公司以约定的（可能高于市场价格）价格购回股票，则不用再承担股价下跌的风险，此时可卖回股票的投资者面对的风险时最小的。所以A错。普通的股票，由于不含有赎回或是卖回的权利，不会被强制赎回或是强制发行方买回。所以对于市场价格的变动，风险都是相对居于中间的。C错误。 如题。是不是错在the most risky，麻烦讲解一下。
NO.PZ2015122801000030 callable common share和putable common share不是看涨期权和看跌期权吗
NO.PZ2015122801000030 老师这里的callable和putable 不能和衍生品里面的call/put option 混为一谈对吧？
When market prigoes up, callable shares are more risky thputable shares for investors. When market prichanges, non-putable, non-callable shares are the most risky for investors. B is correct. When market pririses, the firm hoption to buy bathe shares , therefore investors have limitegains when they holthe callable shares. When market priops, investors csell the shares bato the firm, therefore investors have protection when they holthe putable shares. 价格上升时，公司为什么会以低价再回购股票呀？应该是价格下降吧？
market price是指什么？是利率而不是市场价格吗
