Explanation
DSL (Digital Subscriber Line) uses POTS (Plain Old Telephone Service) lines to provide high-speed internet access. If the POTS lines are not working, it could cause an internet outage for DSL customers. Fiber and cable internet typically use different types of infrastructure, while satellite internet is not reliant on POTS lines. References: CompTIA A+ Certification Exam: Core 1 - Page 231

Explanation
According to the Official CompTIA A+ Core 1 Study Guide (220-1101) , the correct answer is A. Document the findings, actions, and solution in the company knowledge base.
The explanation is that after resolving an issue, a technician should always document what was done and how it was fixed. This helps to create a record of the problem and its solution for future reference and also to share knowledge with other technicians.
https://www.comptia.org/training/books/a-core-1-220-1101-study-guide
By documenting the findings, actions, and solution in the company knowledge base, it will help to ensure that if the Issue happens again, the technician or a different technician will be able to quickly and easily find the solution and resolve the Issue. Additionally, it is important to document the solution so that the same Issue does not need to be troubleshot multiple times in the future.

Explanation
an inverter is a device that converts DC power from the laptop's battery or AC adapter to AC power for the backlight of the LCD panel. If the inverter is defective, the backlight will not work and the LCD panel will appear blank or very dim. The user can still see a faint image if they shine a flashlight into the LCD because the LCD itself is still working.

Explanation
802.11 ax is a wireless networking protocol that utilizes the 5.0GHz frequency and has the best speed and reception among the options given. 802.11 ax offers higher data rates, lower latency, increased capacity, and improved power efficiency than previous protocols. It is also known as Wi-Fi 6 or High Efficiency Wireless (HEW). 802.11a also uses the 5.0GHz frequency, but it is an older protocol that has lower speed and reception than 802.11 ax. 802.11b/g/n use the 2.4GHz frequency, which is more crowded and prone to interference than the 5.0GHz frequency. 802.11n can use both frequencies, but it is also slower and less efficient than 802.11 ax.
Reference: https://www.comptia.org/training/books/a-core-1-220-1101-study-guide (page 82)