Which of the following reduces the risk of Pelvic inflammatory Disease(PID)?

Oral contraceptive Pills reduce the risk od PID by preventing the ascent of bacteria from the vagina, by thickening the cervical mucus (due to the progesterone content) and decresinng motility of the female genital tract (FGT). Mirena, DMPA and progesterone only Pills (POPs) also thicken the cervical mucus and reduce PID. There is no evidence suggesting the reduction of incidence of PID with spermicidal agents. Ref: Shaw&;s textbook of Gynaecology 17th edition Pgno: 264