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
Psychodynamic theory among the following is/are: 
Select and explain. 
A. Psychosexual theory., B. Psychosocial theory., C. Cognitive theory., D. All of the above.
D: All of the above.
Answer: D: All of the above. 
Explanation: I. Psychodynamic theories

 Psychosexual theory   -  Sigmund Freud
 Psychosocial theory    -  Eric Erickson
 Cognitive theory          -  Piaget

II.Behavioural theories

 Hierarchy of needs - Maslow
 Social learning theory - Bandura  
 Classical conditioning - Pavlov 
 Operant conditioning - Skinner