This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Psychoanalysis, Subject name: Psychiatry
Of the following defense mechanisms, which is considered the most mature? 
Select and explain. 
A. Denial, B. Sublimation, C. Dissociation, D. Regression
B: Sublimation
Answer: B: Sublimation 
Explanation: Sublimation: expressing an unacceptable emotion in a socially acceptable way, is classified as a mature defense mechanism. Denial, dissociation, regression, and intellectualization are all classified as less mature defense mechanisms.