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】Learning whether a certain negotiation strategy is good requires observing how that strategy works through several negotiating sessions.