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: Gynaecology & Obstetrics
The risk factors of acute pelvic inflammatory disease (PID) are the following except: 
Select and explain. 
A. Menstruating teenagers who have multiple sex partners, B. IUD users, C. Women with monogamous partner who had vasectomy, D. Previous history of acute PID
C: Women with monogamous partner who had vasectomy
Answer: C: Women with monogamous partner who had vasectomy 
Explanation: None