Retention policies are the guidelines that dictate when to delete data backups based on operational or compliance needs. They specify how long, how, where, and in what format the data backups are stored, and who has authority over them. The other options are not directly related to the deletion of data backups.
https://backup.ninja/news/Database-Backups-101-Backup-Retention-Policy-Considerations

Explanation
A synthetic full backup is a type of backup that combines a full backup with one or more incremental backups to create a new full backup without accessing the source data. This type of backup is suitable for database servers, as it reduces the backup window, minimizes the impact on the server performance, and provides faster recovery time. Verified References: [Synthetic Full Backup]

Explanation
Maintenance and support is a type of license that would most likely include vendor assistance. Maintenance and support is a contract that defines the level and scope of service and assistance that a vendor provides to a customer for using their software product. Maintenance and support may include technical support, bug fixes, patches, updates, upgrades, documentation, training, and other benefits. Maintenance and support licenses usually have an annual fee based on the number of users or devices covered by the contract. Open-source is a type of license that allows free access to the source code and modification and distribution of the software product, but does not guarantee vendor assistance. Version compatibility is not a type of license, but a feature that ensures software products can work with different versions of operating systems or other software products. Subscription is a type of license that allows access to software products for a limited period of time based on recurring payments, but does not necessarily include vendor assistance.References:
https://www.techopedia.com/definition/1440/software-licensinghttps://www.techopedia.com/definition/1032/bus

The administrator is attempting to establish the recovery point objective (RPO) by determining how frequently backups need to be performed on an application server. RPO is a metric that defines how much data can be lost or how far back in time a recovery can go in case of a disaster or disruption, based on the business requirements and impact analysis of an organization or system. RPO is measured by the time interval between backups or snapshots of data, such as hourly, daily, weekly, etc., depending on how critical or sensitive the data is and how often it changes or updates. References: [CompTIA Server+ Certification Exam Objectives], Domain 5.0: Security, Objective 5.3: Given a scenario, explain methods and techniques to secure data.

Explanation
A firewall is a network device or software that filters and controls the incoming and outgoing traffic based on predefined rules. A firewall can block or allow certain types of packets, ports, protocols, or IP addresses. The output of the ping command shows that the local host is unreachable, which means that there is no network connectivity between the source and the destination. This could be caused by a firewall that is blocking the ICMP (Internet Control Message Protocol) packets that ping uses to test the connectivity. References:
https://www.comptia.org/training/resources/exam-objectives/comptia-server-sk0-005-exam-objectives (Objective 2.2)