This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Immunization, Subject name: Pediatrics
Protective levels of Tetanus anti-toxin is: 
Select and explain. 
A. >0.01 IU/mL, B. >0.5 IU/mL, C. >1.0 IU/mL, D. >5 IU/mL
A: >0.01 IU/mL
Answer: A: >0.01 IU/mL 
Explanation: a. >0.01IU/mL(Ref: Nelson's 20/e p 1381, Ghai 8/e p 193-194)Protective titer for diphtheria >0.1IU/mL and for tetanus >0.01IU/mL.