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
1 mL of expectoration contains what number of TB bacilli in an active case of TB? 
Select and explain. 
A. 100, B. 1,000, C. 10,000, D. 1,00,000
B: 1,000
Answer: B: 1,000 
Explanation: None