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
Which part of mind gives instinctual drives to a person to obtain immediate gratification according to structural model of mind? 
Select and explain. 
A. Id, B. Ego, C. Super ego, D. Repressor
A: Id
Answer: A: Id 
Explanation: Id works on "reality principle"
Id is about the innate, instinctual drives of a person that gives him immediate gratifaction such as hunger, anger & sex.