This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Disorders of Parathyroid Gland, Subject name: Medicine
What is the most common presentation of MEN1? 
Select and explain. 
A. Entero-pancreatic tumour, B. Angio-fibroma, C. Pituitary adenoma, D. Parathyroid Adenoma
D: Parathyroid Adenoma
Answer: D: Parathyroid Adenoma 
Explanation: MEN 1 (11q13) Parathyroid adenoma 90% Entero-pancreatic tumour 30-70% Pituitary adenoma 15-50% Associated tumours Angiofibromas Collagenoma 85% 70%