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
Patient of contamination phobia was asked by therapist to follow behind and touch everything he touches in patients house Therapist kept talking quietly & calmly all the time. And the patient was asked to repeat the procedure twice daily. The procedure is 
Select and explain. 
A. Flooding, B. Modelling, C. Positive reinforcement, D. Aversion therapy
B: Modelling
Answer: B: Modelling 
Explanation: B i.e. Modelling