The correct option is (a) 10 – 20 μm
The best explanation: The size of a typical eukaryotic cell is 10 – 20 μm. Prokaryotic cells are generally smaller than eukaryotic cells and also multiply more rapidly. Bacteria, blue-green algae, mycoplasma and PPLO (Pleuro Pneumonia Like Organisms) are the types of prokaryotic cells.