The compare option for a specific rule in the New App Viewer under Policy Optimizer allows an administrator to compare the applications configured in the rule with the applications seen from traffic matching the same rule. This option helps the administrator to identify any discrepancies between the intended and actual applications allowed by the rule. The administrator can then optimize the rule by adding or removing applications as needed1. Option A is incorrect because the compare option does not compare the running configuration with the candidate configuration of the firewall. That is done by using the Commit > Commit and Push option2. Option B is incorrect because the compare option does not compare applications configured in the rule with their dependencies. That is done by using the App Dependencies tab under Policy Optimizer1. Option D is incorrect because the compare option does not compare the security rule with any other security rule selected. That is done by using the Compare Rules option under Policies > Security3.

Explanation/Reference:
Reference: https://www.paloaltonetworks.com/documentation/71/pan-os/pan-os/decryption/configure-ssh- proxy