The correct option is D (a) and (b) above
In barrier methods, ovum and sperms are prevented from physically meeting with the help of barriers. Such methods are available for both males (condoms) and females (cervical caps).
Intra uterine devices (IUDs) are inserted by doctors in the uterus through vagina. IUDs increase phagocytosis of sperms within the uterus and the Cu ions released suppress sperm motility and the fertilising capacity of sperms.