How Do Sociologists Know That the Causes of Eating Disorders

How do sociologists know that the causes of eating disorders (such as anorexia nervosa and bulimia) and obesity reflect social factors more than physical or biological factors?

A) Max Weber clearly showed that their origins lie in the cult of beauty present in the Roman republic.
B) If physical or biological factors were responsible, physicians would have found a cure for such important health issues.
C) Only women suffer from these conditions.
D) They are very recent health problems.