This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Contraceptives, Subject name: Gynaecology & Obstetrics
[{'content': 'The use of combined oral contraceptive pill is associated with an increased incidence of: \nSelect and explain. \nA. Bacterial vaginosis, B. Chlamydial endocervicitis, C. Vaginal was, D. Genital herpes', 'role': 'user'}, {'content': 'Answer: B \nExplanation: There is an overall reduction in the incidence of PID with OCPs but Chlamydial PID may increase. This is classically an indolent PID where the patient has no pain, no discharge.', 'role': 'assistant'}]