The answer is the letter D. Bacteria
*Bacteria is a prokaryote because it lacks a true membrane-bound nucleus and other organelles.
*Euglena- is a eukaryotic and unicellular microorganism. It has a well-defined nucleus and other organelles.
*Amoeba- is a eukaryotic microorganism that has also a membrane-bound nucleus and other organelles.
*Paramecium- is also a eukaryotic microorganism because it has a true nucleus and other membrane-bound organelles.
