The most likely scenario (and correct answer) is that the team breaks down the larger user story into segments that span releases, which couldn’t be tested until the end. The other responses are incorrect because it’s not necessary to
make a user story simpler or to reassess; there’s nothing wrong with a complicated user story crossing iterations. However, the functionality won’t be usable until all segments are complete. Lastly, the break down of a user story has
no effect on how it fits into an iteration.