The detail "...make sure they are not touching each other..." best supports the inference that one bad apple can spoil all the others. As stated in the text, the fruits are stored in the hoard house for future consumption. It is important that one does not contain a bruise since this will also affect the others around it.
The answer is three because Alcinous says this when hearing Odysseus crying
A mistaken belief, especially one based on unsound argument.
