This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Infectious disease, Subject name: Pediatrics
Tuberculin test is said to be positive when there is. 
Select and explain. 
A. Induration, B. Erythema, C. Erythema, induration, D. Induration with blistering
A: Induration
Answer: A: Induration 
Explanation: - A positive tuberculin test is when an induration of diameter 10 mm more is present. - erythema is not taken into account. - It indicates hypersensitivity to tuberculoprotein, denoting infection with tubercle bacilli or BCG immunisation , recent or past with or without clinical disease. Reference : Anathanarayan & paniker&;s 9th edition, pg no: 354,355