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: Surgery
Spontaneous pneumothorax exceeding .....% of chest cavity should have a chest tube inseed - 
Select and explain. 
A. 10, B. 25, C. 45, D. 60
B: 25
Answer: B: 25 
Explanation: Ans. is 'b' i.e., 25 Exact answer according to Schwaz in 30%.