Which content type takes the maximum advantage of web caching mechanisms to boost performance?

Scenario: A Citrix Engineer wants to protect a web application using Citrix Web App Firewall. The engineer enables the Learn action for the Start URL, HTML, Cross-Site Scripting, and HTML SQL Injection protections. The engineer assigns this profile to a policy, which is then bound to the virtual server.
Which two items can the engineer check to determine that the Learn action is NOT capturing any rules? (Choose two.)

Statistics for which three types of violations are presented on the App Security Dashboard?
(Choose three.)

Which two response headers are added by Application Firewall? (Choose two.)

A manager for a hospital billing system wants to display the last four digits of a credit card number when printing invoices.
Which credit card security action does this?