What is the significance of meiosis?

Which of the following statements are correct regarding the importance of meiosis?
$(i)$ It increases the genetic variability in the population of organisms from one generation to the next.
$(ii)$ It decreases genetic variability.
$(iii)$ It occurs in all cells of our body.
$(iv)$ It is an important process for evolution.

In which of the following stages does the centromere not split?

$A$: In higher organisms,a constant number of chromosomes is maintained generation after generation.
$R$: Meiosis occurs during the formation of gametes in plants and animals.

Which process maintains the stability of the chromosome number in the generation produced by sexual reproduction?

What is the primary role of meiosis?