A student reads in a newspaper that the soil in his area contains high levels of arsenic. Based on this information, he believes that his fellow high school classmates have this metal present in their bodies. To test his hypothesis, he conducts an investigation of the soil in his schoolyard to see if it is contaminated with arsenic. He tests seven different areas around the school and finds high levels of arsenic in each. He concludes that the students at the school must have high levels of arsenic in their systems as well. Which of these is the best evaluation of his conclusion? A. His conclusion is valid because he tested enough areas of soil to validate his hypothesis.
B. His conclusion is flawed because he did not test the soil at the homes where the students lived.
C. His conclusion is valid because arsenic is a toxic metal and is easily absorbed by the human body.
D. His conclusion is flawed because he did not test the students to see if their bodies contained metal arsenic.