Explanation
RAID 10 is a combination of RAID 1 and RAID 0, which provides both performance and redundancy. RAID
1 mirrors data across two or more disks, while RAID 0 stripes data across two or more disks. RAID 10 combines these two methods to create a mirrored stripe set, which can tolerate multiple disk failures as long as they are not in the same mirror. RAID 10 requires at least four disks and offers better performance than RAID
5, which uses parity to provide redundancy. References:
https://www.comptia.org/blog/what-is-raid-0-1-5-6-10

The first step in troubleshooting a computer that does not turn on when the power button is pressed is to check if there is any power going to the computer. The technician should reseat or reconnect the power cable to ensure it is firmly attached to both ends, and confirm that the outlet or power strip is providing energy by using a multimeter or another device. This can eliminate any issues with loose or faulty connections or power sources, and help isolate the problem further. Reference: https://partners.comptia.org/docs/default-source/resources/a-core-series-combined-content-guide (page 28)

The most likely reason for this error is
A) The HDD is malfunctioning.
A bootable device not found error usually indicates that the system cannot access or detect the hard disk that contains the operating system files. This could be due to a physical or logical damage to the hard disk, such as bad sectors, corrupted partitions, or faulty cables. According to the web search results, some possible causes and solutions for this error are:
Hard drive connection issue: Check the cabling and power supply to the hard drive and make sure they are properly connected12.
Corrupt hard drive partitions: Use a Windows installation media to scan and repair the corrupt system files using the System File Checker (SFC) tool1.
Damaged hard drive: Replace the hard drive with a new one and reinstall the operating system2.
Incorrect boot sequence in the BIOS: Enter the BIOS or UEFI settings menu and change the boot order to make sure that the system drive is in the first position13.
Damaged MBR (Master Boot Record): Use a Windows installation media to repair the Windows bootloader using the Diskpart tool1.

Explanation
If the filesystem check shows that all files are accessible and the filesystem is clean, but a hard drive error message persists, it's possible that the hard drive is experiencing S.M.A.R.T. (Self-Monitoring, Analysis, and Reporting Technology) failure. This is a warning system built into hard drives to alert users of potential issues before they become critical. References: CompTIA A+ Certification Exam Core 1 Exam Objectives - 3.3 Given a scenario, troubleshoot mobile device issues

Optical fiber is the type of cable that should be used to terminate ST connectors on each end. ST connectors are commonly used for fiber optic cables, which transmit data using light pulses. Coaxial, shielded twisted pair, and HDMI are not types of cables that use ST connectors, but different types of connectors and transmission methods.