The New App-ID characteristic enables the firewall to monitor new applications on the network, so that the engineer can better assess the security policy updates they might want to make. The New App-ID characteristic always matches to only the new App-IDs in the most recently installed content releases. When a new content release is installed, the New App-ID characteristic automatically begins to match only to the new App-IDs in that content release version. This way, the engineer can see how the newly-categorized applications might impact security policy enforcement and make any necessary adjustments. References: Monitor New App-IDs

Explanation
The correct answer is D - QoS can be used on firewalls with multiple virtual systems configured. QoS is a feature that enables network administrators to prioritize and manage network traffic to ensure that critical applications receive the necessary bandwidth and quality of service. This feature can be used on firewalls with multiple virtual systems, allowing administrators to configure policies on a per-Virtual System basis.
Additionally, QoS can be used in conjunction with SSL decryption to ensure that applications running over SSL receive appropriate treatment.

Explanation/Reference:
Reference: https://www.paloaltonetworks.com/documentation/80/pan-os/web-interface-help/network/ network-interfaces/pa-7000-series-layer-2-interface#idd2bcaacc-54b9-4ec9-a1dd-8064499f5b9d

In Palo Alto Networks firewalls, the order of rule evaluation is critical for traffic enforcement. To ensure high priority evaluation, rules should be configured at the top of the rulebase so they are matched before others. The Security Pre-Rules are designed for shared policies across multiple device groups in Panorama, and by placing the block action rules at the top of the Pre-Rules, it guarantees that these rules are evaluated first, before any device-specific or post-rules.
For verification, please refer to the Palo Alto Networks "PAN-OS® Administrator's Guide" or the official configuration documentation for Panorama and device group rules.