A human hair is found to have a high ratio of 18O to 16O. From this information it can be assumed that
a. the person is suffering from a chronic disease such as diabetes.
b. the person has experienced prolonged exposure to radioactivity.
c. the person lives in a region where "heavy" water is consumed.
d. the person regularly uses a protein-rich hair conditioner.
e. the person eats a diet high in cholesterol-rich meat.
Answer: C