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: Dental
Psychoanalytical theory was given by: 
Select and explain. 
A. Freud., B. Eric Erickson., C. Piaget., D. Masler.
A: Freud.
Answer: A: Freud. 
Explanation: None