题目选项分析

John, an expert in game theory, predicts that negotiations cannot be resolved unless one party is willing to concede a symbolic step. He also believes that when a symbolic step of concession is taken, negotiations will be resolved. Other game theory experts, however, believe that these results do not take other variables into account.

Which of the following, if true, best supports the contention in the last sentence?

【选项】Judging the outcome of a particular negotiation requires knowing about other negotiations that have taken place in the past.