Which of the following contraceptive methods has a very high failure rate?

$Cu$ ions released from copper-releasing intrauterine devices $(IUDs)$:

What is the significance of the progesterone-estrogen combination as a contraceptive measure?

Describe the location and function of Diaphragms and Foams in the context of reproductive health.

$A$: Surgical methods block gamete transport and thereby prevent conception.
$R$: The surgical method used in the male for this purpose is called vasectomy.

Which of the following is not a natural method of contraception?