Tubectomy is a method of sterilization in which

$A$ sterilisation technique in females which blocks gamete transport and thereby prevents conception is

$A$ : ‘Saheli’-new oral contraceptive for the females was developed at $CDRI$, Lucknow.
$R$ : It has no steroid in it

$A$ : Lactational amenorrhoea is due to high level of prolactin.
$R$ : Prolactin stimulates the release of gonadotropins

Assertion : Copper $-T$ is an effective contraceptive device in human females.

Reason : Copper $-T$ prevents passage of sperms from vagina upwards into fallopian tubes.