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
Severe hereditary spherocytosis is seen due to the defect of the following protein 
Select and explain. 
A. Spectrin, B. Ankyrin, C. Band 3, D. Band 4.2
A: Spectrin
Answer: A: Spectrin 
Explanation: . Spectrin