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
Reciprocal inhibition is done by - 
Select and explain. 
A. Systemic desensitization, B. Behaviour therapy, C. Flooding, D. All of the above
A: Systemic desensitization
Answer: A: Systemic desensitization 
Explanation: Systemic desensitization is based on the principle of reciprocal inhibition.