What statement best supports the theory that eukaryotic cells evolved through endosymbiosis?

The presence of organelles like mitochondria and chloroplasts with their own DNA and membrane structure closely resembling that of bacteria supports the theory of endosymbiOSis, where a prokaryotic cell engulfed another prokaryotic cell and formed a symbiotic relationship over time. Additionally, the fact that these organelles replicate independently of the host cell and have similarities to certain types of bacteria further strengthens the endosymbiotic theory of eukaryotic cell evolution.