This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Psychiatry
A 25 year old female presents with 2 year history of repetitive, irresistible thoughts of contamination with dirt associated with repetitive hand washing. She reports these thoughts to be her own and distressing but is not able to overcome them along with medication. She is most likely to benefit from which of the following therapies - 
Select and explain. 
A. Exposure and response prevention, B. Systematic desensitization, C. Assertiveness training, D. Sensate focusing
A: Exposure and response prevention
Answer: A: Exposure and response prevention 
Explanation: The most useful behavioral therapy in OCD is exposure with response prevention.