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: Social & Preventive Medicine
Which of the following statements is true about BCG vaccination ? 
Select and explain. 
A. Distilled water is used as diluent for BCG vaccine, B. The site for injection should be cleaned thoroughly with spirit, C. WHO recommends Danish 1331 strain for vaccine production, D. Mantoux test becomes positive after 48 hours of vaccination
C: WHO recommends Danish 1331 strain for vaccine production
Answer: C: WHO recommends Danish 1331 strain for vaccine production 
Explanation: None