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
Type 5 hypersensitivity reaction is modification of ? 
Select and explain. 
A. 1, B. 2, C. 3, D. 4
B: 2
Answer: B: 2 
Explanation: Ans. is 'b' i.e., 2