Medical studies have shown that eating vitamin and mineral supplements does not significantly help the human body, and sometimes even causes harm to the human body. Some doctors have given advice to stop eating vitamin and mineral supplements and instead should use a balanced diet. Supplement your body with vitamins and minerals. Which of the following, if true, would most weaken the results of the above study? ? ['A 7-year follow-up survey of 30,000 women found that taking vitamin D plus calcium supplements did not harm their bodies.', 'An 8-year follow-up survey of 10,000 men showed that not taking vitamins and mineral supplements did not increase their risk of disease.', 'A controlled survey of 10,000 elderly people in developed and underdeveloped regions showed no significant differences in their health status.', 'A 3-year follow-up survey of 20,000 children shows that children who do not take vitamins and mineral supplements have a higher incidence of malnutrition.']