Homologous chromosomes differ from sister chromatids because A: sister chromatids cannot be separated from one another, while homologous chromosomes can.

B: homologous chromosomes are formed after replication, while sister chromatids exist prior to S phase of interphase.

C: homologous chromosomes are identical copies, while sister chromatids are only similar in gene location.

D: sister chromatids are identical copies, while homologous chromosomes may differ in the allele present.