One of the most effective ways to defend against malicious actors targeting home routers for DDoS attacks is to change the default credentials of the router. The default credentials are often well-known or easily guessed by attackers, who can then access and compromise the router settings and firmware. By changing the default credentials to strong and unique ones, a technician can prevent unauthorized access and configuration changes to the router. Adding network content filtering may help block some malicious or unwanted websites but may not prevent attackers from exploiting router vulnerabilities or backdoors. Disabling the SSID broadcast may help reduce the visibility of the wireless network but may not prevent attackers from scanning or detecting it.
Configuring port forwarding may help direct incoming traffic to specific devices or services but may not prevent attackers from sending malicious packets or requests to the router. References: CompTIA A+ Core 2 (220-1002) Certification Exam Objectives Version 4.0, Domain 3.3

Explanation
The strongest wireless configuration is B.
WPA3. WPA3 is the most up-to-date wireless encryption protocol and is the most secure choice. It replaces PSK with SAE, a more secure way to do the initial key exchange. At the same time, the session key size of WPA3 increases to 128-bit in WPA3-Personal mode and 192-bit in WPA3-Enterprise, which makes the password harder to crack than the previous Wi-Fi security standards
https://www.makeuseof.com/tag/wep-wpa-wpa2-wpa3-explained/

The law firm wants to retain more versions of the backups when possible, so the best backup method for the technician to implement in this scenario would be Incremental backup. Incremental backups only save the changes made since the last backup, which allows for more frequent backups and minimizes the amount of storage required. This would allow the law firm to retain more than three versions of backups without risking backup failure.
To retain more versions of backups, the technician should implement an Incremental backup method12 An incremental backup method only backs up the data that has changed since the last backup, so it requires less storage space than a full backup12

Navigate to the Windows 10 Settings menu, select the Accounts submenu, select Sign in options, select Windows Hello Fingerprint, and have the user place a fingerprint on the fingerprint reader repeatedly until Windows indicates setup is complete. Windows Hello Fingerprint can be set up by navigating to the Windows
10 Settings menu, selecting the Accounts submenu, selecting Sign in options, and then selecting Windows Hello Fingerprint. The user will then be asked to place a fingerprint on the fingerprint reader repeatedly until Windows indicates that setup is complete. Windows Hello Fingerprint allows the user to log into the laptop using just their fingerprint, providing an additional layer of security.

The most likely reason that the system is not utilizing all the available RAM is that it is running a 32-bit OS. A 32-bit OS can only address up to 4GB of RAM, and some of that is reserved for hardware and system use1. Therefore, even if the technician installed 8GB of RAM, the system can only use around 3.5GB of usable RAM. To use the full 8GB of RAM, the technician would need to install a 64-bit OS, which can address much more memory2. The system missing updates, the system's memory failing, or the system requiring BIOS updates are not likely to cause this issue.
References: 2: https://support.microsoft.com/en-us/windows/windows-10-system-requirements-6d4e9a79-
66bf-7950-467c-795cf0386715 1: https://www.makeuseof.com/tag/unlock-64gb-ram-32-bit-windows-pae- patch/