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
Primary role of T-Lymphocytes is - 
Select and explain. 
A. Antibody formation, B. Delayed hypersensitivity, C. Complement production, D. All of the above
B: Delayed hypersensitivity
Answer: B: Delayed hypersensitivity 
Explanation: Ans. is 'b' i.e., Delayed hypersensitivity