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
Mutation in Marfan's syndrome g is ? 
Select and explain. 
A. Fibrillin I, B. Fibrillin II, C. Collagen I, D. Collagen IV
A: Fibrillin I
Answer: A: Fibrillin I 
Explanation: Ans. is 'a' i.e., Fibrillin I