The correct answer is B. 22.
Port 22 is the default port for SSH (Secure Shell), a protocol that allows secure and encrypted remote login and command execution over a network. SSH uses public key cryptography to authenticate the client and the server, and to encrypt the data exchanged between them. SSH can be accessed through different ports, depending on the configuration of the server and the client. The default port for SSH is 22, but it can be changed to any other port for security reasons1.
Port 20 is the default port for FTP (File Transfer Protocol) data transfer, a protocol that allows file transfer between a client and a server over a network. FTP uses two ports: one for data transfer (port 20) and one for control commands (port 21). FTP does not provide encryption or authentication, and it is vulnerable to various attacks, such as packet sniffing, spoofing, or brute force. To secure FTP connections, protocols such as FTPS (FTP over SSL) or SFTP (SSH File Transfer Protocol) can be used2.
Port 23 is the default port for Telnet, a protocol that allows remote login and command execution over a network. Telnet does not provide encryption or authentication, and it sends data in plain text, which can be easily intercepted or modified by attackers. Telnet is considered obsolete and insecure, and it should be replaced by SSH or other secure protocols3.
Port 25 is the default port for SMTP (Simple Mail Transfer Protocol), a protocol that allows sending and receiving email messages over a network. SMTP does not provide encryption or authentication, and it can be exploited by spammers or hackers to send malicious or unwanted emails. To secure SMTP connections, protocols such as SMTPS (SMTP over SSL) or STARTTLS (Transport Layer Security) can be used.
Therefore, port 22 is the only port that allows for secure communications by default, as it uses SSH protocol.
For more information about ports and their security, you can refer to the following web search results: How to secure your TCP/IP ports, What is an SSL port? A technical guide for HTTPS, HTTPS Port: What It Is, How to Use It, and More (2023).

Explanation
A CPU fan is a component that cools down the CPU, which is the main processor of the computer. If the CPU fan is failing, it can cause the computer to slow down and the fans to alternate between silent and very loud12.
This is because the CPU fan cannot maintain a consistent speed and airflow to keep the CPU at a safe temperature. When the CPU gets too hot, it throttles its performance to avoid overheating, which results in a slower computer. The other fans in the computer also try to compensate for the lack of cooling from the CPU fan by spinning faster and louder2

Explanation
Primary Array:
Drag and drop two 120 GB SSD hard drives to the primary array bay.
Open the primary array and select RAID 1 as the RAID level. RAID 1 provides fault tolerance of one drive, ability to function with only one drive, easily recoverable data, high redundancy, and very fast on reads. It also does not need to be scalable and uses the minimum number of drives (two) for RAID 1.
Confirm the configuration and close the primary array.
Secondary Array:
Drag and drop two 300 GB SSD hard drives to the secondary array bay.
Open the secondary array and select RAID 0 as the RAID level. RAID 0 provides the best write performance and uses the minimum number of drives (two) for RAID 0. It also provides a total space of
600 GB (300 GB x 2), which meets the requirement.
Confirm the configuration and close the secondary array.
You have completed the configuration of the storage arrays.

https://www.resonatenetworks.com/2020/04/29/clustering-vs-load-balancing-whats-the-difference/ A load balancer distributes network traffic evenly across multiple servers, ensuring each server is being properly utilized. This helps to prevent overloading of any individual server, which can cause downtime or slow response times for users. In this scenario, adding a load balancer would be the best way to ensure the new servers are being properly utilized. References: CompTIA A+ Certification Exam: Core 1 - Page 181