The correct option is
A Ribosomes
DNA is a genetic material which is mainly present in the nucleus of the cell in eukaryotes. In prokaryotes, they lie freely in the cytoplasm. The functional segments of the DNA are known as genes. Mitochondria and chloroplast are the only organelles which are semi-autonomous which have their own DNA. Mitochondrial DNA is known as mt-DNA and the chloroplast is known as ct-DNA.
So, the correct answer is option B.