Final answer:
A zero-sum conflict approach may be necessary when compromise would result in an illegal outcome, as it involves situations where one party's gain is inherently another's loss. Option b.
Step-by-step explanation:
When might a zero-sum conflict approach be necessary? A zero-sum conflict approach may become necessary (b) when compromise would break a law. This would occur when the choices available in a negotiation or conflict resolution scenario are mutually exclusive, and reaching a compromise would result in an illegal outcome, thereby rendering compromise unacceptable. In a zero-sum scenario, one party's gain is another's loss, which often aligns with situations involving strict legal standards that cannot be bent or reinterpreted to allow for a middle ground. A real-world example might include bargaining scenarios between political parties or within legal proceedings where the potential outcomes are binary — such as legalizing a particular action or keeping it banned.