A public health student lists three areas to study in nutrition: (A) the molecular composition of foods, (B) human physiology and metabolism, and (C) cultural reasons why people eat certain foods. Which statement best describes why these three areas together make nutrition complex?

• A. Because human physiology is so simple that chemistry and culture alone determine all nutritional outcomes.
• B. Because only cultural reasons determine diet, while chemistry and human biology are minor and inconsequential compared to social choices.
• C. Because food chemistry, human biology, and social/behavioral determinants interact to produce health outcomes, so single-factor explanations are often insufficient.
• D. Because once the chemical composition of a food is known, it alone can predict a person's long-term health regardless of biology or behavior.

Answer: (C)