B选项错在哪里呢？

NO.PZ2023061903000053 问题如下 Q. A large country can: A.benefit imposing a tariff. B.benefit with export subsi. C.not benefit from any tra restriction. A is correct. finition, a large country is big enough to affethe worlpriof its imports anexports. A large country cbenefit imposing a tariff if its terms of tra improve enough to outweigh the welfare loss arising from inefficient allocation of resources.A正确。根据定义，一个大国大到足以影响其进出口商品的世界价格。如果一个大国的贸易条件得到改善，足以抵消资源配置效率低下所造成的福利损失，那么它就可以通过征收关税获益。 BC怎么理解

NO.PZ2023061903000053问题如下Q. A large country can:A.benefit imposing a tariff.B.benefit with export subsi.C.not benefit from any tra restriction. A is correct. finition, a large country is big enough to affethe worlpriof its imports anexports. A large country cbenefit imposing a tariff if its terms of tra improve enough to outweigh the welfare loss arising from inefficient allocation of resources.A正确。根据定义，一个大国大到足以影响其进出口商品的世界价格。如果一个大国的贸易条件得到改善，足以抵消资源配置效率低下所造成的福利损失，那么它就可以通过征收关税获益。 解析没看懂，麻烦一下这题知识点是什么并如何理解，谢谢！