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
Which of the following is not arisk factor for pelvic inflammatory disease 
Select and explain. 
A. N. gonorrhoeae, B. Bacterial vaginosis, C. Trichomonas vaginalis, D. Chlamydia trachomatis
B: Bacterial vaginosis
Answer: B: Bacterial vaginosis 
Explanation: Bacterial vaginosis is not a risk factor for PID development.