Design a brief experimental comparison (no lab work required) to test the hypothesis that eating a high-fat meal before drinking reduces peak BAC more in males than females because of greater gastric ADH activity in males. Which key elements must be included to control confounders and justify your evaluation?

• A. Use a cohort study that enrolls people who habitually drink with meals, compare their self-reported peak drunkenness to those who drink fasted, and attribute differences to gastric ADH without measuring BAC or controlling for dose or composition.
• B. Recruit only males to avoid sex differences, administer variable alcohol doses based on reported tolerance rather than weight, measure BAC once at an arbitrary time point after drinking, and infer sex effects from literature comparisons.
• C. Randomized cross-over design with male and female groups matched for body weight and composition, standardized alcohol dose per body weight, control sessions fasting vs. fed (high-fat), timed BAC sampling, and statistical testing of sex × meal interaction to identify differential reduction in peak BAC.
• D. Give participants different types of alcohol across days (beer, wine, spirits) without standardization, and conclude that any observed differences are due to meal effects rather than beverage ethanol content variability.

Answer: (C)