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
It is probable that physician have a higher index of suspicion for tuberculosis in children without BCG scar that those with BCG scar. If this is so and an association is found between Tuberculosis and not having BCG due to -scar, the association may be 
Select and explain. 
A. Selection bias, B. Interviewer bias, C. Surveillance bias, D. Non-response bias
B: Interviewer bias
Answer: B: Interviewer bias 
Explanation: None