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 is true about tuberculin test? 
Select and explain. 
A. It gives the immune status of patient, B. It tells about prior exposure to Mycobacterium tuberculosis only, C. It may be negative in dissociated tuberculosis, D. It is highly positive in a post measles case
C: It may be negative in dissociated tuberculosis
Answer: C: It may be negative in dissociated tuberculosis 
Explanation: None