The correct option is D Separation of chromatids
During meiosis II, the sister chromatids within the two daughter cells separate, forming four new haploid gametes. The mechanics of meiosis II is similar to mitosis, except that each dividing cell has only one set of homologous chromosomes.
During meiosis II, the sister chromatids within the two daughter cells separate, forming four new haploid gametes. In anaphase II, the sister chromatids of the homologous pair separate and are pulled away from each other towards the opposite poles of the cell.
Therefore, each cell has half the number of sister chromatids to separate out as a diploid cell undergoing mitosis.
Isolation of sex chromosomes and homologous chromosomes, occurs in meiosis I and synthesis of DNA and centromere occurs during interphase.
So, the correct answer is "seperation of chromatids", which specifically occurs during meiosis II.