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
Interval cholecystectomy surgery is 
Select and explain. 
A. Clean, B. Clean contaminated, C. Contaminated, D. Dirty
B: Clean contaminated
Answer: B: Clean contaminated 
Explanation: When there is no information but entry to genitourinary or gastrointestinal systems it is clean contaminated.