Correct Answer (Detailed Explanation is Below)
A.
Bacterium
Detailed Explanation
Bacteria are prokaryotic organisms. Prokaryotic cells do not possess a membrane-bound nucleus or membrane-bound organelles such as mitochondria. Their genetic material is located in a nucleoid region. The two major groups of prokaryotes are
Bacteria and Archaea. In contrast, amoeba and yeast are eukaryotic organisms with a true nucleus.