Which hormone of the female body is suppressed by the oral contraceptive pills?

Identify the false statement regarding the techniques of contraception.
$I$. There are many side effects of tubectomy and vasectomy.
$II$. The purpose of tubectomy is to prevent egg formation.
$III$. The most important component of the oral contraceptive pill is progesterone.
$IV$. Contraceptive oral pills help in birth control by preventing ovulation.

Differentiate between the natural method of family planning and the artificial method of family planning.

The best way to decrease the population growth of a country is:

$Statement 1$: Use of condoms is a safeguard against $AIDS$ and sexual diseases besides checking pregnancy.
$Statement 2$: Certain contraceptives are planted under the skin of the upper arm to prevent pregnancy.

How many devices are included in Intra Uterine Devices (IUDs) from the following list: Lippes loop,Multiload $375$,Cu-$T$,$LNG$-$20$,Condom,Diaphragm,Cervical Cap,Vaults?