Final answer:
The mitochondrion contains its own DNA and ribosomes, supporting its role as a cell's power plant and the endosymbiotic theory.
Step-by-step explanation:
The correct option that contains its own DNA and ribosomes is the mitochondrion. Mitochondria are unique organelles that have their own DNA, which is separate from the DNA found in the nucleus of the cell. Additionally, they contain their own ribosomes, which are similar to those found in prokaryotic cells. Mitochondria are often referred to as the power plants of the cell because they produce most of the cell's supply of adenosine triphosphate (ATP), the cell's main energy-carrying molecule.
The endosymbiotic theory suggests that mitochondria were once independent prokaryotic organisms that entered into a symbiotic relationship with an ancestral eukaryotic cell. A key piece of evidence for this theory is the presence of mitochondrial DNA and ribosomes, which indicates that mitochondria have some of the capabilities of autonomous living entities.