Homologous chromosomes are separated during the following phases:
a. Anaphase I - In meiosis I, homologous chromosomes are separated and moved to opposite poles of the cell.
b. Anaphase II - In meiosis II, sister chromatids (which are already copies of each other) are separated, but this does not involve homologous chromosomes separating.
c. Anaphase during mitosis - In mitosis, sister chromatids are separated, but again, this does not involve homologous chromosomes.
So, the answer is: a. Anaphase I is the phase during which homologous chromosomes are separated from one another.