In which phase of mitosis do chromatids,each possessing an independent centromere,form?

The centromere splits during

Select the correct option on the basis of the following events:
$(I)$ Chromosomes cluster at opposite spindle poles.
$(II)$ Nuclear envelope assembles around the chromosome clusters.
$(III)$ Golgi complex and $ER$ reform.

When dividing cells are examined under a light microscope,chromosomes become visible in

The space is found between which of the following?

During which phase does chromosome decondensation occur?