The action that could lead to foodborne illness from cross-contamination is chopping meat and vegetables on the same cutting board. This practice can transfer harmful bacteria from the raw meat to the vegetables, which may not be cooked before consumption, increasing the risk of foodborne illness.
While the other options also pose food safety risks (e.g., eating undercooked chicken, thawing meat improperly, and not refrigerating cut fruit quickly), they are not specifically related to cross-contamination.