This question basically tests the analytical capability of the candidate.
The answer can be given as:
You need to work with PO and to update the test cases one needs to understand the exact requirement. The agile tester must also understand the risk involved in changing the requirement every time. Keeping all this aside the agile tester must also be able to write the test cases and generic test plan. One must not go for the automation until and unless the requirements are finalized.