Final answer:
A bacteria's cytoplasm contains both DNA and enzymes, where DNA is located in the nucleoid region and enzymes are involved in metabolic processes.
Step-by-step explanation:
A bacteria's cytoplasm contains several structures, including ribosomes, a cytoskeleton, and genetic material. Specifically, the genetic material is typically a single circular strand of DNA, which is located in a region of the cell called the nucleoid. In addition to DNA, the cytoplasm also contains enzymes that are involved in various metabolic processes. Therefore, the correct answer to the question 'A bacteria's cytoplasm contains ________.' would be D. both DNA and enzymes.