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
Pernicious anemia occur due to 
Select and explain. 
A. Failure of secretion of Vit B12, B. Failure of secretion of intrinsic factor, C. Failure of absorption of intrinsic factor, D. Folate deficiency
B: Failure of secretion of intrinsic factor
Answer: B: Failure of secretion of intrinsic factor 
Explanation: None