When we look at the temporary mounts of onion peel as well as human cheek cells, we can see a large region of each cell enclosed by the cell membrane. This region takes up very little stain because:
(a) The stain is repelled by the cell membrane
(b) The region is composed mainly of cytoplasm
(c) The region lacks organelles that can be stained
(d) The stain is too diluted in the temporary mounts
