The correct response is:
Prokaryotic cell because it does not have a nucleus, which would look like a solid circle in the cell.
This conclusion is based on the characteristics of prokaryotic and eukaryotic cells. Prokaryotic cells lack a nucleus and typically do not have membrane-bound organelles, while eukaryotic cells have both a nucleus and various membrane-bound organelles. Since the description indicates the absence of a nucleus, it is indicative of a prokaryotic cell.