Answer:
The correct answer is - obsessive-compulsive disorder.
Explanation:
Obsessive-compulsive disorder or OCD is a condition or disorder in which a person can not control his thought or fear about anything that is not necessary. It leads to repetitive behavior.
In this case, Alex has impulsive and repetitive behavior to wash his hand again and again due to fear of germs.
Thus, the correct answer is - obsessive-compulsive disorder.