While working with the cork through his homemade microscope he viewed some small compartments having empty spaces surrounded by walls which he called cells. Therefore Robert hook is credited to discover the unit of life that is cell.
Later scientists like Matthias Schleiden and Theodor Schwann gave the cell theory. Cell theory says that each organism is made up of cells and the cell is the smallest unit from which life is made up of and new cells can come from old cells only. So it was Robert Hooke who discovered small compartments which he called cells.
For this problem, the most probable and the most likely answer for this would be the second option which is cells.
When viewing, not just corks, but other things under a microscope, may it be a home-made one or of something in value or a technologically advanced microscope, small compartments would always be visible under these lenses and they are cells. Some might look like boxes but they are cells. These cells might come in many sizes, but they will always be cells. Cells are everywhere.
