The main factor in increasing the population is

Zero growth of population is indicated by

Given below are two statements:
Statement-$I$: $A$ population growing in a habitat with limited resources shows initially a lag phase.
Statement-$II$: $A$ population growing in a habitat with limited resources shows finally an asymptote phase.

$A$: Environmental resistance operates to slow down the exponential phase in logistic population growth.
$R$: $A$ crash phase does not occur in this population.

Certain characteristic demographic features of developing countries are:

Graph $A$ and $B$ indicate: