老师，可否讲解一下公式long asset+short forward=long risk free

NO.PZ2018062007000051问题如下 Whiof the following statements best scribes put-call-forwarparity?A.A ficiary call is equivalent to a protective put with a forwarcontract.B.A ficiary call is equivalent to a protective put.C.A ficiary call is equivalent to the combination of short put plus long risk-free bonanlong a forwarcontract. A is correct. Accorng to put-call-forwarpartiy, a ficiary call is equivalent to synthetic protective put.中文解析C+K=P+S，ficiary call=protective putlong asset+short forwarlong risk free bon(购买有风险的资产同时short forwar以转移风险，获得无风险收益）那么long asset=long risk free bon+long forwar risk free bon面值为FP，将long asset=long bonlong forwar入 protective put，即P+S=long put+long bon 面值为FP）+long forwar等式右边也称为protective put with forwar们可以发现无论期末股票价格如何变化， ficiary call 与 synthetic protective put 的结果是相同的。既然期末的outcome是相同的，所以期初构建两个portfolio的成本也应该相同。ficiary call的成本=C0+K/(1+rf）^T，而synthetic protective put 的成本为P0+FP/(1+rf）^T( long forwar初不支付现金，所以没有成本）这样就能得到put call parity with forwar公式了，即C0+K/(1+rf）^T=P0+FP/(1+rf）^T 请问B怎么错了呢，没搞懂

NO.PZ2018062007000051 问题如下 Whiof the following statements best scribes put-call-forwarparity? A.A ficiary call is equivalent to a protective put with a forwarcontract. B.A ficiary call is equivalent to a protective put. C.A ficiary call is equivalent to the combination of short put plus long risk-free bonanlong a forwarcontract. A is correct. Accorng to put-call-forwarpartiy, a ficiary call is equivalent to synthetic protective put.中文解析C+K=P+S，ficiary call=protective putlong asset+short forwarlong risk free bon(购买有风险的资产同时short forwar以转移风险，获得无风险收益）那么long asset=long risk free bon+long forwar risk free bon面值为FP，将long asset=long bonlong forwar入 protective put，即P+S=long put+long bon 面值为FP）+long forwar等式右边也称为protective put with forwar们可以发现无论期末股票价格如何变化， ficiary call 与 synthetic protective put 的结果是相同的。既然期末的outcome是相同的，所以期初构建两个portfolio的成本也应该相同。ficiary call的成本=C0+K/(1+rf）^T，而synthetic protective put 的成本为P0+FP/(1+rf）^T( long forwar初不支付现金，所以没有成本）这样就能得到put call parity with forwar公式了，即C0+K/(1+rf）^T=P0+FP/(1+rf）^T 左边是Ficiary call，右边是Protective put，正好相等。

NO.PZ2018062007000051 问题如下 Whiof the following statements best scribes put-call-forwarparity? A.A ficiary call is equivalent to a protective put with a forwarcontract. B.A ficiary call is equivalent to a protective put. C.A ficiary call is equivalent to the combination of short put plus long risk-free bonanlong a forwarcontract. A is correct. Accorng to put-call-forwarpartiy, a ficiary call is equivalent to synthetic protective put.中文解析C+K=P+S，ficiary call=protective putlong asset+short forwarlong risk free bon(购买有风险的资产同时short forwar以转移风险，获得无风险收益）那么long asset=long risk free bon+long forwar risk free bon面值为FP，将long asset=long bonlong forwar入 protective put，即P+S=long put+long bon 面值为FP）+long forwar等式右边也称为protective put with forwar们可以发现无论期末股票价格如何变化， ficiary call 与 synthetic protective put 的结果是相同的。既然期末的outcome是相同的，所以期初构建两个portfolio的成本也应该相同。ficiary call的成本=C0+K/(1+rf）^T，而synthetic protective put 的成本为P0+FP/(1+rf）^T( long forwar初不支付现金，所以没有成本）这样就能得到put call parity with forwar公式了，即C0+K/(1+rf）^T=P0+FP/(1+rf）^T 就因为没有FORWAR

NO.PZ2018062007000051 问题如下 Whiof the following statements best scribes put-call-forwarparity? A.A ficiary call is equivalent to a protective put with a forwarcontract. B.A ficiary call is equivalent to a protective put. C.A ficiary call is equivalent to the combination of short put plus long risk-free bonanlong a forwarcontract. A is correct. Accorng to put-call-forwarpartiy, a ficiary call is equivalent to a protective put with a forwarcontract.中文解析C+K=P+S，ficiary call=protective putlong asset+short forwarlong risk free bon(购买有风险的资产同时short forwar以转移风险，获得无风险收益）那么long asset=long risk free bon+long forwar risk free bon面值为FP，将long asset=long bonlong forwar入 protective put，即P+S=long put+long bon 面值为FP）+long forwar等式右边也称为protective put with forwar们可以发现无论期末股票价格如何变化， ficiary call与protective put with forwar结果是相同的。既然期末的outcome是相同的，所以期初构建两个portfolio的成本也应该相同。ficiary call的成本=C0+K/(1+rf）^T，而protective put with forwar成本为P0+FP/(1+rf）^T( long forwar初不支付现金，所以没有成本）这样就能得到put call parity with forwar公式了，即C0+K/(1+rf）^T=P0+FP/(1+rf）^T 代入 protective put，即P+S=long put+long bon 面值为FP）+long forwar等式右边也称为protective put with forwar请问protective put 难道不是long asset+long put吗？