Explanation
The best tool to identify the correct cable is C. Toner probe.
A toner probe is a device that can be used to locate and trace a specific cable within a network rack or a wall outlet. A toner probe consists of two parts: a tone generator and a tone detector. The tone generator is connected to one end of the cable and sends an audible signal through the cable. The tone detector is used to scan the other end of the cable and pick up the signal. The tone detector emits a sound or a light when it detects the signal, indicating the correct cable.
A toner probe can be useful for network technicians who need to locate an end user's Cat 6 cable within a network rack that is poorly documented and has no cable management system. A Cat 6 cable is a type of twisted pair cable that can support high-speed data transmission over Ethernet networks. A network rack is a frame that holds network equipment, such as servers, switches, routers, or patch panels. A cable management system is a set of devices or methods that organize and secure the cables within a network rack .
The other options are not the best tools to identify the correct cable, because they have different purposes or limitations. A cable tester (option A) is a device that can be used to test the functionality and quality of a cable, such as its continuity, resistance, or interference. A cable tester can help diagnose and troubleshoot faulty cables, but it cannot locate or trace specific cables within a network rack. A network tap (option B) is a device that can be used to monitor and analyze the traffic and data that pass through a network. A network tap can help capture and inspect network packets, but it cannot locate or trace specific cables within a network rack. A loopback plug (option D) is a device that can be used to test the functionality and connectivity of a port or an interface. A loopback plug can help verify if a port or an interface is working properly, but it cannot locate or trace specific cables within a network rack.
For more information about toner probes and other network tools, you can refer to the following web search results: [What Is a Toner Probe?], [What Is Cat 6 Cable?], [What Is a Network Rack?], [What Is a Cable Tester?], [What Is a Network Tap?], [What Is a Loopback Plug?].

Explanation
If a technician made several upgrades to a computer and then determined the power supplied by the PSU is insufficient, the upgraded graphics card and adding more RAM would most likely cause the insufficiency.
Upgrading the graphics card and adding more RAM can increase the power consumption of a computer, which can cause the power supplied by the PSU to be insufficient.
Adding more RAM and upgrading the graphics card are the most likely causes of the insufficiency of power supplied by the PSU. These upgrades require more power to operate efficiently and can cause the PSU to become insufficient.

Explanation
RAID stands for Redundant Array of Independent Disks, which is a technology that combines multiple disks into a logical unit to improve performance, reliability, or both. There are different types of RAID levels that use different methods of data distribution and redundancy.
RAID 0 is a level that stripes data across multiple disks without any redundancy. It offers the highest performance but no fault tolerance. If any disk fails, the entire array is lost.
RAID 1 is a level that mirrors data across two disks. It offers the lowest performance but the highest fault tolerance. It can survive the failure of one disk.
RAID 5 is a level that stripes data across multiple disks with parity information. It offers a balance between performance and fault tolerance. It can survive the failure of one disk, but not two or more disks.
RAID 10 is a level that combines RAID 1 and RAID 0. It creates a striped array of mirrored pairs. It offers high performance and high fault tolerance. It can survive the failure of one disk in each pair, or multiple disks in different pairs.
Therefore, if the server administrator wants to rebuild the array to withstand a potential multidrive failure in the future, RAID 10 is the most likely choice.

Explanation
Verifying the correct type of paper is loaded is the best solution for resolving the issue of blank receipts being printed by a point-of-sale printer. Some receipt printers require a specific type of paper, and using the wrong type can result in blank receipts. References:
https://www.techwalla.com/articles/what-are-the-causes-of-blank-receipts-from-a-printer Top of Form Verify the correct type of paper is loaded. If a point-of-sale printer is printing blank receipts, one possible cause could be that the wrong type of paper is loaded in the printer. Thermal printers require thermal paper to print properly. If regular paper is loaded instead of thermal paper, the printer will not be able to produce an image on the paper and will print blank receipts.

Explanation
A defective battery is the most likely cause of a mobile phone that gets really hot to the touch, does not retain a charge, and is slow while charging. A defective battery can cause the phone to overheat and may also cause performance issues. References: CompTIA A+ Certification Exam Objectives 1001, 2.14