Barrier methods are the one that prevents sperms from reaching egg and thereby inhibit fertilization. Copper-releasing IUDs release copper that suppresses the sperm motility which in turn reduces its fertilizing capacity. IUDs, that release levonorgestrel (LNG), cause endometrial atrophy and alter the stroma to inhibit implantation. It also increases sperm phagocytosis in the uterus. Oral contraceptive pills contain small doses of estradiols or progesterone. The higher blood level of progesterone exerts negative feedback on FSH and LH secretion by anterior pituitary which are the enzymes of follicle maturation and ovulation. Thus, contraceptive pills inhibit ovulation. Vasectomy refers to a surgical method in which vasa deferentia in human males are cut and sealed to prevent pregnancy by making seminal fluid devoid of sperms. Thus, the correct answer is option D.