Answer:
They concluded that the cell is eukaryotic cell.
Explanation:
Prokaryotic and eukaryotic cells are the two types of organisms. Prokaryotic organisms are the organisms made up of prokaryotic cells and eukaryotic organisms are made up of eukaryotic cells.
Prokaryotic cells do not have a nucleus and other membrane-bound organelle and eukaryotic cells have a nucleus and other membrane-bound organelles like mitochondria.
Therefore if the cell has mitochondria they must conclude that the cell is eukaryotic because the prokaryotic cell does not have mitochondria as it is a membrane-bound organelle.