The correct answer is D. Nucleus.
The nucleus is a membrane-bound organelle found in eukaryotic cells. It contains the cell’s genetic material, which is organized into chromosomes. The nucleus is responsible for controlling the cell’s activities and for regulating its growth and division.
Mitochondria are organelles found in eukaryotic cells that are responsible for energy production. They are not the site of DNA storage.
DNA is a molecule that contains the genetic code of an organism. It is found in the nucleus of eukaryotic cells and in the cytoplasm of prokaryotic cells.
RNA is a molecule that is involved in protein synthesis. It is found in the nucleus, cytoplasm, and ribosomes of eukaryotic cells.