A scratch on the scanning bed of a copier can cause a solid black line to appear on all copies, as the scanner cannot read the original document properly through the scratch. The scratch can also reflect light and create noise in the scanned image. The printing function is unaffected by the scratch, as it does not use the scanning bed. The technician should inspect and clean the scanning bed, and replace it if necessary. Reference:
https://partners.comptia.org/docs/default-source/resources/a-core-1-content-guide (page 16)

The unexpected reboots on a graphics workstation when rendering complex 3-D models may be caused by insufficient power supply. The workstation is configured with a 115V power supply that is rated at 200W, which may not be enough when the GPU is heavily tasked. The technician should begin troubleshooting by checking the power supply.

The most likely reason the data transfer failed is D. The older phone utilized different wireless protocols.
Wireless protocols are the standards that devices use to communicate with each other over a wireless network.
Different wireless protocols have different features, such as speed, range, security, and compatibility. If the older phone and the new phone use different wireless protocols, they may not be able to transfer data smoothly or at all. For example, if the older phone uses Wi-Fi Direct and the new phone uses Bluetooth, they may not be able to connect or recognize each other.
To avoid this problem, you should make sure that both devices support the same wireless protocol and that they are in range of each other. You can also use a third-party app or service that can transfer data between different devices, such as Smart Switch1 or Move to iOS2. These apps can help you transfer data such as contacts, photos, messages, and more from your old phone to your new phone.
References:
2: Failure of data transfer from android to ... - Apple Community
1: Smart Switch Transfer Issues - Samsung Electronics America

The most likely cause of the wireless network connectivity issues is A. External interference.
External interference is any signal or noise that disrupts or degrades the quality of a wireless network. External interference can come from various sources, such as other wireless networks, cordless phones, microwaves, Bluetooth devices, or electrical appliances. External interference can affect the wireless network performance, reliability, and security, by causing issues such as signal loss, packet drops, latency, or interference.
In this scenario, a company in a large building uses a wireless network for its workstations. After a new company moves into the building on the floor below, the old company's wireless network begins experiencing connectivity issues. This could indicate that the new company's wireless network is using the same or overlapping frequency channel as the old company's wireless network, and creating external interference.
Wireless networks use radio frequency channels to transmit and receive data, and each channel has a certain bandwidth and range. If two or more wireless networks use the same or overlapping channel, they may interfere with each other and cause congestion or collision.
To resolve this issue, the old company's network technician should change the wireless network channel to a different one that is less crowded or more compatible with the wireless network standard. The technician should also check the wireless network settings and features, such as SSID (Service Set Identifier), encryption, authentication, or power level, and adjust them if necessary. The technician should also scan the wireless environment and identify the sources and levels of external interference, and try to avoid or minimize them if possible.
For more information about external interference and how to prevent or reduce it, you can refer to the following web search results: [What Is Wireless Interference?], [How to Find the Best WiFi Channel for Your Router], [How to Reduce Wireless Interference].

The Unified Extensible Firmware Interface (UEFI) is the setting that should be checked when a computer is not booting from a flash drive containing an OS image. UEFI is a modern firmware that replaces the traditional BIOS and includes a "Secure Boot" feature that can prevent unauthorized operating systems from loading during the system's boot process. This security feature might be the reason the computer cannot access the flash drive before loading the OS. Disabling Secure Boot or adjusting the boot order within the UEFI settings can allow the system to boot from the flash drive. This is supported by the CompTIA A+ Core 1 (220-1101) Exam Objectives, particularly in sections 1.4 "Given a scenario set up and configure accessories and ports of mobile devices" and 4.0 "Virtualization and Cloud Computing", emphasizing the importance of UEFI settings in boot processes and virtualization .