A. Birth control pills(oral contraceptives) check ovulation in female by inhibiting the secretion of FSH and LH that are necessary for ovulation.
B. Condom is a mechanical barrier method which checks pregnancy by preventing deposition of semen in the vagina.
C. Vasectomy is a sterilization method in male in which they are capable of ejaculation, but the latter consists only of secretions of various glands, and has no sperms.
D. Copper-T- It is a intrauterine device which prevent implantation.
So, the correct answer is 'A-3, B-1, C-4, D-2'.