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 the brain is most commonly effected in Alzheimer's disease? 
Select and explain. 
A. Locus ceruleus, B. Entorhinal cortex, C. Frontal cortex, D. Cerebellum
B: Entorhinal cortex
Answer: B: Entorhinal cortex 
Explanation: "Entorbinal cortex / Medial temporal lobe" is most commonly affected in Alzheimer's disease.