Explanation
According to the Palo Alto Networks documentation , decryption consumes firewall CPU resources, so it is important to evaluate the amount of SSL decryption that the firewall deployment can support. Two factors that affect the CPU consumption are the TLS protocol version and the encryption algorithm used by the encrypted traffic. The newer versions of TLS (such as TLS 1.3) and the stronger encryption algorithms (such as AES-256-GCM) require more CPU resources to decrypt than the older versions and weaker algorithms.
Therefore, the correct answer is B and C.
The other options are not relevant or important for sizing a decryption firewall deployment:
Number of blocked sessions: This option refers to the number of sessions that the firewall blocks based on Security policy rules. It does not affect the decryption performance or resource consumption.
Number of security zones in decryption policies: This option refers to the number of security zones that are used to define the source and destination of the traffic to be decrypted. It does not affect the decryption performance or resource consumption.
References: 1:
https://docs.paloaltonetworks.com/pan-os/9-1/pan-os-admin/decryption/prepare-to-deploy-decryption/size-the-de

Explanation
https://docs.paloaltonetworks.com/pan-os/10-2/pan-os-web-interface-help/device/device-high-availability/ha-link

Explanation
When the egress guaranteed bandwidth is exceeded, the firewall passes traffic on a best-effort basis.
https://docs.paloaltonetworks.com/pan-os/11-0/pan-os-admin/quality-of-service/qos-concepts/qos-bandwidth-ma

Explanation
The valid qualifiers for a Decryption Policy Rule match are:
* Source Zone
* Destination Zone
* Source Address
* Destination Address
* Source User
* Destination User
* Source Region
* Destination Region
* Service/URL Category
* Custom URL Category
* URL Filtering Profile
Therefore, out of the options given, Destination Zone, Custom URL Category, and User-ID are valid qualifiers. References:
https://docs.paloaltonetworks.com/pan-os/10-1/pan-os-admin/decryption/configure-decryption-policies.html

Explanation
https://docs.paloaltonetworks.com/best-practices/10-2/decryption-best-practices/decryption-best-practices/plan-s
https://live.paloaltonetworks.com/t5/general-topics/decrypt-guest-network-traffic/td-p/119388