To use the Symantec LiveUpdate server for pre-release content, the administrator should edit the LiveUpdate Policy. This policy controls how endpoints receive updates from Symantec, including options for pre-release content.

Purpose of the LiveUpdate Policy: The LiveUpdate Policy is specifically designed to manage update settings, including source servers, scheduling, and content types. By adjusting this policy, administrators can configure endpoints to access pre-release content from Symantec's servers.

Pre-Release Content Access: Enabling pre-release content within the LiveUpdate Policy allows endpoints to test new security definitions and updates before they are generally available. This can be beneficial for organizations that want to evaluate updates in advance.

Policy Configuration for Symantec Server Access: The LiveUpdate Policy can be set to point to the Symantec LiveUpdate server, allowing endpoints to fetch content directly from Symantec, including any available beta or pre-release updates.

Explanation of Why Other Options Are Less Likely:

Option A (System Policy) and Option C (System Schedule Policy) do not govern update settings.

Option D (Firewall Policy) controls network access rules and would not manage LiveUpdate configurations.

Therefore, to configure access to the Symantec LiveUpdate server for pre-release content, the LiveUpdate Policy is the correct policy to edit.