Final answer:
The nucleoid is a region in prokaryotic cells where the bacterial chromosome is located. The nucleoid contains the bacterial DNA and is not surrounded by a membrane, making option C) the correct answer.
Step-by-step explanation:
The nucleoid in prokaryotic cells is a region within the cytoplasm where the bacterial chromosome, which is typically a large circular strand of DNA, is located. Unlike eukaryotic cells, prokaryotic cells do not have a true nucleus; hence, their DNA is not enclosed by a nuclear membrane. Therefore, the nucleoid is not surrounded by a membrane, nor does it only contain RNA molecules. Instead, it contains bacterial DNA along with some associated proteins that help in organizing and packing the DNA within the cell.
According to these characteristics, the correct answer is C) contains a bacterial chromosome. This is because the nucleoid is essentially a region where the genetic material of a bacterium is concentrated and is not bound by a membrane. Additionally, the presence of RNA alone would not constitute the nucleoid, as its key component is indeed the bacterial chromosome.