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
All are features of Silico-tuberculosis except 
Select and explain. 
A. High sputum AFB +ve, B. Children of such cases do not get disease, C. Impairement of total lung, D. Nodular fibrosis
A: High sputum AFB +ve
Answer: A: High sputum AFB +ve 
Explanation: In recent years doubts have risen in the association between silicois and tuberculosis as:

Sputum is rarely AfB+
Children and women of sts do not develop tuberculosis
Post mortem of sts fail to prove existence of tuberculosis
Radilogical evidence of both conditions is similar.