How do Intrauterine Devices $(IUDs)$ function as a method of birth control?

$IUDs$ within .......... of coitus have been found to be very effective as emergency contraceptives as they could be used to avoid possible pregnancy due to rape or casual unprotected intercourse. (in $hours$)

Which of the following functions are true for copper ions released by copper-releasing $IUDs$?
$I -$ Suppress sperm motility
$II -$ Inhibit the fertilizing capacity of sperms
$III -$ Make the uterus unsuitable for implantation
$IV -$ Make the cervix hostile to sperms

In vasectomy, a small part of the $vas \text{ } deferens$ is removed through a small incision on the scrotum.

Match the contraceptive methods given under column-$I$ with their examples given under column-$II$. Select the correct choice from those given below.

Column $I$	Column $II$
$A$. Chemical	$p$. Tubectomy and vasectomy
$B$. $IUDs$	$q$. Copper $T$ and loop
$C$. Barriers	$r$. Condom and cervical cap
$D$. Sterilisation	$s$. Spermicidal jelly and foam
	$t$. Coitus interruptus and calendar method

What is the primary purpose of female sterilization (tubectomy)?