Which of the following is not a natural/traditional contraceptive...

The correct answer is option (3) as Vault is a barrier method of contraception which is made of rubber that is inserted into the female reproductive tract to cover the cervix during the coitus. - Option (1) is incorrect as periodic abstinence is also a natural method of contraception in which couples avoid coitus during the fertile period. - Option (2) is incorrect as lactational amenorrhea is also a natural method of contraception which is based on the fact that ovulation and therefore the cycle do not occur during the period of intense lactational following parturition. - Option (4) is incorrect as coitus interruptus is a natural method of contraception in which male partner withdraws his penis from the vagina just before ejaculation so as to avoid insemination.