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 person brings gifts for her wife next day after having fight with her. This is an example of 
Select and explain. 
A. Reaction formation, B. Aim inhibition, C. Undoing, D. Suppression
C: Undoing
Answer: C: Undoing 
Explanation: Undoing is a neurotic defense mechanism where an act is done to nullify a previous act.