Explanation
Application consistent backup is a method of backing up data that ensures the integrity and consistency of the application state. It involves notifying the application to flush its data from memory to disk and quiescing any write operations before taking a snapshot of the data. If the databases were not backed up to be application consistent, they might contain incomplete or corrupted data that cannot be restored properly.
References:
CompTIA Server+ Certification Exam Objectives1, page 12
What is Application Consistent Backup and How to Achieve It2
Application-Consistent Backups3

Explanation
The audit.log file is a file that records security-related events on a Linux server, such as user login, file access, and system commands. The logrotate utility is a tool that rotates, compresses, and deletes old log files based on certain criteria, such as size, time, or frequency. To decrease the number of times the log rotates without losing any information, the administrator should increase the audit.log file size in the appropriate configuration file, such as /etc/logrotate.conf or /etc/logrotate.d/auditd. Verified References: [audit.log], [logrotate]

Insider threat is the most likely system vulnerability in a company that deploys antivirus, anti-malware, and firewalls that can be assumed to be functioning properly. An insider threat is a malicious or negligent act by an authorized user of a system or network that compromises the security or integrity of the system or network. An insider threat can include data theft, sabotage, espionage, fraud, or other types of attacks. Antivirus, anti-malware, and firewalls are security tools that can protect a system or network from external threats, such as viruses, worms, ransomware, or open ports. However, these tools cannot prevent an insider threat from exploiting their access privileges or credentials to harm the system or network.

QSFP+ (Quad Small Form-factor Pluggable Plus) connectors are used in high-density, high-speed networking solutions such as 40 Gigabit Ethernet (40GbE) interfaces. When upgrading a server's network to 40Gbps, QSFP+ is the appropriate choice due to its capability to support such high-speed data transfer rates. 10 GigE, SFP, and SFP+ connectors are used for lower speed connections (10Gbps and below for SFP+ and 10 GigE, and even less for SFP), making them unsuitable for a 40Gbps network upgrade.