The answer to this is C. For those who are not too aware of what prophase is, this is the first stage of cell division. This is the time when the chromosomes start to become more visible. The nuclear envelope and the chromatids start to disappear.
Even the nucleolus disappears at this point in time. It is in this stage wherein DNA has already been replicated. When you check the order of the chromosomes under a microscope, they are already visible. This can be delightful to people who find this fascinating.