Assume that the Food and Drug Administration (FDA), using proper procedures, adopts a rule covering future investigations involving the FDA’s regulation of food additives. According to the new rule, the FDA will not regulate food additives without giving food companies an opportunity to cross-examine witnesses. Some time later, the FDA regulates methylisocyanate, a food additive. In its investigation of methylisocyanate, the FDA has not allowed producers to cross-examine witnesses. Producers protest, saying that the FDA promised cross-examination. The FDA responds that the Administrative Procedure Act does not require such cross-examination and that it can freely withdraw the promise made in its new rule. If the producers challenge the FDA in a court, on what basis could the court rule in their favor?