Answer: Option A
Step-by-step explanation:
Brushing the teeth every hour because one feels dirty is a mental disorder because practically it is not possible that the mouth gets dirty every hour.
Even if someone has a habit of eating, no one brushes the teeth every hour. I is a type of mental disorder in which the person feels that his mouth is dirty and brushes again and again throughout the day.
Rest of the other options are normal and they are normal reaction of the person based on the situation in which they are placed.