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: Pathology
Which of the following is most often involved in Multiple Endocrine Neoplasia 1 (MEN 1): 
Select and explain. 
A. Pituitary, B. Pancreas, C. Parathyroid, D. Thyroid
C: Parathyroid
Answer: C: Parathyroid 
Explanation: Parathyroid