What happens during interkinesis?

Meiosis-$II$ resembles which of the following processes?

The non-sister chromatids twist around and exchange segments with each other during

$A$: 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.

The number of chromosome groups at the equatorial plate in metaphase-$I$ of meiosis in a plant with $2n = 50$ shall be:

In meiosis,at which stage does the chromosome number actually become halved?