Which statement about anorexia nervosa and bulimia nervosa is true?
a. approximately half of those with anorexia nervosa go on to develop bulimia nervosa, indicating that the two disorders may not be distinct but may represent phases of the same eating disorder.
b. the binge eating/purging type of bulimia nervosa is different from anorexia nervosa in that it involves both low weight and amenorrhea.