In negotiations, what does back-up mean?

having a plan so you can walk away
splitting the difference
meeting halfway in a deal
hiding how much you can really spend

You were given an exceptional iq so obviously you made valedictorian to change the tone of the sentence from resentful to complimentary, without changing the central meaning, which word most needs to be replaced? o a. exceptional o b. valedictorian o c. given o d. obviously