A wireless controller is used to manage a corporate WLAN, providing centralized management and configuration of access points. References: CompTIA Network+ Certification Study Guide, Chapter 8:
Wireless Networks.

Jumbo frames are Ethernet frames that can carry more than the standard 1,500 bytes of payload data. Jumbo frames can support payloads of up to 9,000 bytes, depending on the network device and configuration. Jumbo frames can improve network performance by reducing the overhead of packet headers and increasing the efficiency of data transmission. Jumbo frames can also reduce the CPU utilization of the sender and receiver devices, as they require fewer interrupts and processing cycles. However, jumbo frames also have some drawbacks, such as increased latency, fragmentation, and compatibility issues. Therefore, jumbo frames should be used with caution and only in networks that support them end-to-end.
A technician who is configuring a bandwidth-monitoring tool that supports payloads of 1,600 bytes should enable jumbo frames for this tool, as this would allow the tool to capture and analyze more data per frame and provide more accurate and detailed results. However, the technician should also ensure that the network devices and interfaces that the tool is connected to also support jumbo frames, and that the MTU (maximum transmission unit) is set to the same value across the network path.
Reference
What are Jumbo Frames?
How to Enable Jumbo Frames
CompTIA Network+ Certification All-in-One Exam Guide, Eighth Edition (Exam N10-008)

Explanation
CNAME stands for Canonical Name, and it is a type of DNS record that creates an alias for another domain name. A CNAME record can be used to redirect a network resource that has been moved to a different location, such as a SaaS solution. For example, if a web server that was previously hosted on the local network with the domain name www.example.com is now hosted by a SaaS provider with the domain name www.saasprovider.com, a CNAME record can be created to point www.example.com to www.saasprovider.com. This way, the users can still access the web server using the original domain name, and the DNS server will resolve it to the new domain name.
References
CNAME is one of the common DNS record types covered in Objective 1.6 of the CompTIA Network+ N10-008 certification exam1.
CNAME can be used to redirect a network resource that has been moved to a different location23.
CNAME creates an alias for another domain name23.
1: CompTIA Network+ Certification Exam Objectives, page 4 2: DNS Record Types - N10-008 CompTIA Network+ : 1.6 3: The Official CompTIA Network+ Student Guide (Exam N10-008), Chapter 1, page 32

A /27 subnet mask has 32 IP addresses, of which 30 are usable for hosts. This is the smallest subnet that can accommodate 31 laptops, as the other options have either too few or too many IP addresses. A /27 subnet mask is equivalent to 255.255.255.224 in decimal notation, and has a wildcard mask of 0.0.0.31. The network address is 10.10.10.0, and the broadcast address is 10.10.10.31. The usable host range is 10.10.10.1 to
10.10.10.30.
References
1: Subnet Cheat Sheet - 24 Subnet Mask, 30, 26, 27, 29, and other IP Address CIDR Network References
2: IP Subnet Calculator

CRC errors are cyclic redundancy check errors that occur when data is corrupted during transmission. CRC errors are usually caused by physical layer issues such as faulty cables, connectors, ports, or interference. The network administrator will most likely start to troubleshoot at layer 1 of the OSI model, which is the physical layer that deals with the transmission of bits over a medium. References: CompTIA Network+ Certification Exam Objectives Version 2.0 (Exam Number: N10-006), Domain 4.0 Network Troubleshooting and Tools, Objective 4.1 Given a scenario, implement network troubleshooting methodology.