Hello. You did not present the cubes to which the question refers, which makes it impossible for me to be able to answer your question exactly, but I will try to help you in the best possible way.
The cell that will have the easiest movement of materials in and out of itself is the cell with the smallest size. This is because, smaller cells have a proportional surface area and volume. This helps in absorbing everything the cell needs, with impressive speed, as well as facilitating the removal of substances harmful to the cell.