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
Major fibril protein in Primary Amyloidosis is ? 
Select and explain. 
A. AL, B. AA, C. Transthyretin, D. Procalciton
A: AL
Answer: A: AL 
Explanation: Ans. is 'a' i.e., AL