在题目中,有一句话是a study has shown that if the registration discount is equal to at least half the potential savings of an attendee's particular cost-saving strategy, the attendee is more likely to reserve the room within the block. 在1C中,HMHPA的registration discount是25,petential cost saving 是2*(104-79),为什么还要选rob stratagy 呢,想不通,求解答,万分感谢啊