Answer: A)Bulimia nervosa.
Step-by-step explanation:
Bulimia nervosa is considered a eating disorder in which a person tends to eat a lot and later feels guilty or purges.People try to eliminate the gained weight through lot of eating.They tend to eat large food amount in short amount of time.
According to question, roommate is facing bulimia nervosa as she is eating lot of snacks in short time and later becomes anxious and shameful for such act.She is also having stomach and tooth related issues.
Other options are incorrect because normal eating habit,binge eating disorder and anorexia nervosa are not disorder whose symptoms is shown by roommate.Thus, the correct option is option(A).