The diagram shows a bivalent at prophase-$I$ of meiosis. Which of the four chromatids can cross over?

Which of the following statements is consistent with meiosis?

During the $Zygotene$ stage,how many chromatids does each pair of homologous chromosomes actually contain?

In which phase do the chromatids separate even at the site of chiasmata formation?

Which of the following statement$(s)$ is/are not correct about meiosis?
$I.$ Meiosis involves pairing of homologous chromosomes and recombination between them.
$II.$ Two diploid cells are formed at the end of meiosis-$II$.
$III.$ Meiosis involves two sequential cycles of nuclear and cell division called meiosis-$I$ and meiosis-$II$,but only a single cycle of $DNA$ replication.
$IV.$ Meiosis-$I$ is initiated after the parental chromosome replication which produces identical sister chromatids at the $S$-phase.
The correct option is

In meiosis,the number of chromosomes is ..............