问题如下图：
选项：
A. 
B. 
C. 
解释：
请问选项B与C能解释一下吗
NO.PZ2016031201000012问题如下 Whiof the following characteristiis least likely to a benefit associatewith using rivatives?A.More effective management of riskB.Payoffs similto those associatewith the unrlyingC.Greater opportunities to go short comparewith the spot market B is correct.One of the benefits of rivative markets is thrivatives create trang strategies not otherwise possible in the unrlying spot market, thus proving opportunities for more effective risk management thsimply replicating the payoff of the unrlying. A is incorrebecause effective risk management is one of the primary purposes associatewith rivative markets. C is incorrebecause one of the operationaantages associatewith rivatives is thit is easier to go short compareto the unrlying spot market. 中文解析本题问的是以下哪个不是优点。A说，衍生品市场可以更有效的管理风险，这确实是它的优点。对应了讲义上的第一条优点Risk allocation, transfer anmanagement.C的意思是，衍生品市场比现货市场有更多做空的机会。这也是它的优点之一，对应了讲义上第三点operationaantages.我们再来看B，衍生品并不是用来复制基础资产头寸的payoff的，它们的payoff是不一样的。比如你手上有一个股票，价格为20， 担心股票 价格下降，long put，put执行价格为18。 期末股票价格下降到10，现货的payoff=-10,但put option payoff=8，两者是不一样的。因此选根据解析中的例子，怎么求出put option payoff=8呢？ Put option :poff max(0,X/ST )20-18 =2 我的理解如上，请问我这里哪里出错了呢?
NO.PZ2016031201000012 问题如下 Whiof the following characteristiis least likely to a benefit associatewith using rivatives? A.More effective management of risk B.Payoffs similto those associatewith the unrlying C.Greater opportunities to go short comparewith the spot market B is correct.One of the benefits of rivative markets is thrivatives create trang strategies not otherwise possible in the unrlying spot market, thus proving opportunities for more effective risk management thsimply replicating the payoff of the unrlying. A is incorrebecause effective risk management is one of the primary purposes associatewith rivative markets. C is incorrebecause one of the operationaantages associatewith rivatives is thit is easier to go short compareto the unrlying spot market. 中文解析本题问的是以下哪个不是优点。A说，衍生品市场可以更有效的管理风险，这确实是它的优点。对应了讲义上的第一条优点Risk allocation, transfer anmanagement.C的意思是，衍生品市场比现货市场有更多做空的机会。这也是它的优点之一，对应了讲义上第三点operationaantages.我们再来看B，衍生品并不是用来复制基础资产头寸的payoff的，它们的payoff是不一样的。比如你手上有一个股票，价格为20， 担心股票 价格下降，long put，put执行价格为18。 期末股票价格下降到10，现货的payoff=-10,但put option payoff=8，两者是不一样的。因此选 所以与现货相比。做空机会更多吗？
做错了，可能不理解这个题的意思，谢谢
