Correct Answer (Detailed Explanation is Below)
A.
Amoeba
Detailed Explanation
Amoeba is a unicellular eukaryotic organism. It consists of a single cell that performs functions such as nutrition, movement, respiration and reproduction. Its cell contains a true nucleus and membrane-bound organelles. Other examples of unicellular eukaryotes include
Paramecium, Euglena and many yeasts.