This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: FMGE 2019, Subject name: Gynaecology & Obstetrics
Most common organism causing pelvic inflammatory disease? 
Select and explain. 
A. Neisseria gonorrhea, B. Gardnerella Vaginalis, C. Bacteroides, D. Chlamydia
D: Chlamydia
Answer: D: Chlamydia 
Explanation: PID Causes: Chlamydia: most prevalent; indolent Gonorrhea: most common in OPD Mycoplasma TB Ureaplasma Bacteroides Pepto streptococcus Bacterial vaginosis Streptococcus