Test learners' ability to apply Chevron deference and arbitrary-and-capricious review to challenges to federal agency rulemakings by (1) identifying when Chevron Step One or Step Two applies, (2) analyzing statutory ambiguity and whether an agency's interpretation is permissible, and (3) evaluating whether a rule satisfies the Administrative Procedure Act's reasoned-decisionmaking requirements (consideration of the record, alternatives, changed positions, reliance interests, and avoidance of post hoc rationalizations). Include short fact patterns requiring students to choose and justify the applicable standard of review, assess the agency's legal and factual reasoning, and recommend likely judicial outcomes and remedies (remand, vacatur, or affirmation).