Which groups are identified as having the highest risk for severe outcomes from foodborne illness?

• A. Professional athletes and people who follow strict calorie-restricted diets because they have higher metabolic demands and therefore worse outcomes with typical gastrointestinal infections.
• B. Healthy middle-aged adults with regular access to medical care who rarely eat food prepared outside the home and thus have lower exposure risk.
• C. Teenagers who exercise frequently and adults with active lifestyles who consume high-protein diets at most meals.
• D. Elderly people, infants, and immunocompromised individuals.

Answer: (D)