Which factor most directly explains why a person who eats diverse foods from supermarkets in developed countries is unlikely to be selenium-deficient, despite living in a region with low soil selenium?

• A. All fruits and vegetables naturally hyperaccumulate selenium regardless of soil content, guaranteeing sufficient intake for everyone who eats produce.
• B. Selenium accumulates in household tap water in developed areas and that single source alone prevents deficiency regardless of diet.
• C. Modern food supply chains mix foods from many growing regions, including selenium-replete areas, so supermarket consumers typically receive selenium from imported or nonlocal sources.
• D. People in developed countries synthesize selenium endogenously when consuming processed foods, making soil selenium irrelevant.

Answer: (C)