The answer is; E
This shows that these organelles were once free-living organisms with their own mechanisms for reproduction which they have retained even after years of symbiotic relationship with the higher organisms. During their duplication, they also replicate their own DNA. Their DNA does not have histones (as opposed to the DNA in the nucleus of their host eukaryotic cell) similar to that of simple organisms such as bacteria.
Meiosis in reproductive organs (testes and ovary) produce gametes. Each human cell including reproductive cells contains 23 pair of chromosomes. Meiosis separates the two chromosomes from each pair thus, each gamete receives only one copy of each chromosome. Therefore, each gamete has 23 new chromosomes, one from each of the 23 pairs. During meiosis, exchange of chromosome segment between copies of a pair of chromosomes. The exchange of chromosome segments creates new combinations of genes which enhances genetic variability within a species.