フリー問題

問題文

A company must decide whether to keep an allow entry for a partner sender indefinitely. Which reasoning is correct?

選択肢

1. Allow entries expire automatically after 30 days in every case, so no review is needed and the company simply re-creates the entry if the partner's mail starts being quarantined again.
2. An allow entry must always be permanent, because reviewing it means removing it to see whether the mail is still trapped, and that experiment interrupts the partner's correspondence every time it is run.
3. An allow entry has no security cost, so it can be permanent, because the entry names one specific sender and the filters continue to inspect everything that sender actually sends for malicious content.
4. An allow entry weakens the protection that applies to that particular path, so it should be time-bound and reviewed rather than being left in place long after the reason for it has gone.