Cu ions released from copper-releasing Intra Uterine Devices (IUDs)

Step-by-step solution

Cu ions release by copper-releasing intrauterine devices suppresses sperm motility. Intrauterine devices are inserted by doctors in the uterus through the vagina. They are available as the non-medicated IUDs, copper-releasing IUDs, and hormone-releasing IUDs, these IUDs increase phagocytosis of sperms within the uterus and the Cu ions suppress sperm's motility and fertilizing capacity. So, the correct answer is 'Suppress sperm motility'.