Crossing over takes place between which chromatids and in which stage of the cell cycle?
(A) Non-sister chromatids of nonhomologous chromosomes at Pachytene stage of prophase I
(B) Non-sister chromatids of nonhomologous chromosomes at Zygotene stage of prophase I
(C) Non-sister chromatids of homologous chromosomes at Pachytene stage of prophase I
(D) Non-sister chromatids of homologous chromosomes at Zygotene stage of prophase I