This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Pelvic Inflammatory Disease, Subject name: Gynaecology & Obstetrics
[{'content': 'PID is most commonly caused by - \nSelect and explain. \nA. Chlamydia, B. Mycoplasma, C. Tubercular bacillus, D. E.Coli', 'role': 'user'}, {'content': "Answer: A \nExplanation: Ans. is 'a' i.e., Chlamydia Sexually transmitted diseases are the most common cause of PIP.o Gonococcal & Chlamydial infections are the most common,o Mycoplasma hominis & genitalumo Tubercular bacilluso Viruseso E. colio Polymicrobial (both aerobe & anaerobs)", 'role': 'assistant'}]