After enabling ATP on the Sophos Firewall, what configuration may prevent the block page from appearing?

The correct choice highlights that when the policy is set to "Log Only," it can prevent the block page from appearing. In this configuration, the firewall logs the activity but does not actively block the traffic associated with any detected threats or malicious activity. As a result, instead of users being presented with a block page when they encounter a threat or suspicious activity, they would merely see the normal traffic flow continued without interruption or alert.

This is significant in contexts where the objective may be to allow users to access content while still monitoring for security threats. However, since no blocking action is taken in this scenario, the users remain unaware of potential risks as there would be no block page displayed.

In contrast, if policies are set to "Allow," "ATP feature not activated," or have "All Traffic allowed," these configurations align with allowing traffic through without interruptions or blocks, which would also not trigger the visibility of a block page. Nonetheless, "Log Only" specifically denotes an intention to monitor without engagement, making it the most relevant option for the question posed.