Cells (A) and (F) show an early and a late stage of the same phase of mitosis. What phase is it?

(Note: You will find the stages in the attached files)

The phase is PROPHASE. Cell A is in early prophase, while cell F is in late prophase.

Explanation:  

The prophase might be divided into early prophase and late prophase.

Early-Prophase: The chromatin is condensed enough to distinguish individual chromosomes. There are also two pares of centrioles located outside the nucleus. They begin the separation from each other, migrating to the opposite poles. The microtubules extend and originate the polar fibers of the mitotic spindle. By this time, nucleoles have already disappeared. In the A cell, you can see the condensing chromatin and the centrioles migrating to the poles, but not there yet. You can also see the intact nuclear membrane and no nucleole. Late-Prophase: The nuclear membrane breaks and disperses. Chromosomes keep condensing until they are completely condensed and in direct contact with the cytoplasm. Each pair of centrosomes is already in the cell poles, and the polar fibers of the mitotic spindle are completely developed, as well as the kinetochore fibers. In the F cell, you can see centrioles in the poles and the noticeable mitotic spindle. You can also see the nuclear membrane broken into many pieces and the chromosomes that are completely condensed.