Answer:
The correct answer would be prophase.
Prophase is the first stage of mitosis during which:
- The chromatin coils and compact to form chromosomes. After replication (in S phase) the chromosome consists of two sister chromatids attached at centromere.
- The mitotic spindle made up of microtubules starts to form at the two ends of the cell.
- In late prophase, structures like nuceolus and nuclear membrane disappear and chromosomes are completely condensed.
