Which of the following statements best supports the claim that certain organelles within eukaryotic cells evolved from free-living prokaryotic cells?

a) The cytoplasm of both eukaryotes and prokaryotes is surrounded by a plasma membrane.
b) Eukaryotes and prokaryotes both contain ribosomes, but the ribosomes of eukaryotes are more complex in structure than those of prokaryotes.
c) Eukaryotes exchange segments of internal membranes between the endoplasmic reticulum and Golgi apparatus, but prokaryotes have no such internal membranes.
d) Some organelles contain their own DNA that is more similar to prokaryotic DNA in structure and function than to the eukaryotic DNA found in the cells' nucleus.

"Some organelles contain their own DNA that is more similar to prokaryotic DNA in structure and function than to the eukaryotic DNA found in the cells' nucleus."

Explanation:

Endosymbiotic Theory:

According to the endosymbiotic theory many prokaryotic cells came closer and formed a much complex cellular structure, which was then termed as a eukaryotic cell. Before, the formation of the eukaryotic cells there were free floating organelles which after evolution came closer and formed the eukaryotic cell in general.

For example:The Mitochondria and plastids inside the plant cells, were first free floating but then they formed a symbiosis and gave rise to a more complex cellular structure called as the eukaryotic cell.

Andreas Schimper:

A botanist who carried out the analysis of determining the possibility that eukaryotes cells evolved from the prokaryotic cells,due the change inside the cellular body formation occurred some million of years before. Which turned everything into a form of symbiotic relationship with one another. The organelles which were first free now are in symbiosis with another.

As he analysed the plastids and the mitochondria(which is the power house of the cell). They had some DNA or genetic material stands which looked more similar to that of that the prokaryotic cells DNA.So, it made it very clear that once these cell organelles were free living, as they had there genetics material to flow from one cell into another. And now the organelles are in the symbiotic association with another inside a eukaryotic cell.