At which phase of meiosis,bivalent chromosomes align on the equatorial plate $:-$

Condensation of chromosomes occurs in

$A$: In the diplotene sub-stage,the two chromosomes of a homologous pair move away from each other.
$R$: The connection is maintained at the site where crossing over has occurred in homologous chromosomes.

Assertion: Meiosis results in the production of haploid cells.
Reason: Synapsis occurs during leptotene.

What is the number of chromatids in a bivalent of homologous chromosomes during synapsis?

In meiosis,the chromosome number becomes