Wrong - the blue color of all the colonies indicates that the lacZ gene remained intact in all plasmids. This means that no incorporation of DNA into any of the plasmids has occurred at the time the cDNA library was constructed. This is unlikely. Perhaps, you did not transform the bacteria with the right plasmids (those containing the cDNA library).

Possible but highly unlikely. If all colonies are white, apparently they all contain plasmids that contain cDNA fragments of the library. Usually the cDNA incorporation into the plasmids during library construction is not that efficient. Possibly, you forgot to add the substrate of lacZ to the plate, and so you cannot distinguish between colonies containing bare plasmids and those containing plasmids that incorporated cDNA fragments when the library was constructed.

Wrong - there are no bacteria on this plate! Unfortunately, virtual science does not allow you to smell the plates and experience the differences. (You'll have to take our word.)

Perhaps you used plates with the wrong antibiotics.

Try again.