Assume that the Food and Drug Administration (FDA), using proper procedures, adopts a rule describing its future investigations. This new rule covers all future circumstances in which the FDA wants to regulate food additives. Under the new rule, the FDA is not to regulate food additives without giving food companies an opportunity to cross-examine witnesses. At a subsequent time, the FDA wants to regulate methylisocyanate, a food additive. The FDA undertakes an informal rulemaking procedure, without cross-examination, and regulates methylisocyanate. Producers protest, saying that the FDA promised them the opportunity for cross examination. The FDA responds that the Administrative Procedure Act does not require such cross-examination and that it is free to withdraw the promise made in its new rule. If the producers challenge the FDA in court, on what basis would the court rule in their favor?