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 fundamental technique used in psychoanalysis is : 
Select and explain. 
A. Concentration, B. Hyponsis, C. Empathy, D. Free association
D: Free association
Answer: D: Free association 
Explanation: D. i.e. Free association