Find the odd one out $w.r.t.$ Saheli.

The most important component of contraceptive pills is:

The chemical method of contraception includes:

Condoms are made up of a thin rubber/latex sheath which is used to cover:

Copper ion-releasing $(IUDs)$ are more efficient than non-medicated methods. Why?

$A$: Surgical methods,also called sterilization,are generally advised for the male/female partner as a terminal method to prevent any more pregnancies.
$R$: These techniques are highly effective but their reversibility is poor.