Bassett group M/J'18 kaplan kit- part a) i and ii) Operating segments

If you study business risks and how audit risk/RoMM relate to business risks - Chapter 11 - for revenue/profits/liquidity etc to change is business risk - and the auditor may indeed be able to confirm by obtaining sufficient appropriate audit evidence that the fluctuation is due to a genuine business reason. But it could be due to misstatement - e.g. expenses of one operating segment have been misallocated to another. The auditor should not dismiss the possibility of misstatement merely because there could be a genuine business reason for a change.

Yes - I think that is the most obvious possible misstatements that could give rise to the fluctuation.