Birth rate is directly proportional to

$Statement \; 1$: Zero population growth should be achieved as early as possible to control human population.
$Statement \; 2$: This requires not two children per couple but a little more effort on reduction of this number.

Choose the correct causes for the population growth.
$I$. Decline in death rate
$II$. Rapid increase in $MMR$ and $IMR$
$III$. Rapid decline in $MMR$ and $IMR$
$IV$. Increase in the number of people in the reproductive age group
$V$. Rapid increase in the death rate

In India,the population growth:

Population explosion occurs due to

The main cause of population explosion in the world is: