Explanation
If a laser printer is producing output with duplicate images (also known as ghost images), it could be due to an issue with the toner drums and rollers. The first step to eliminate the ghost images would be to clean the toner drums and rollers to remove any excess toner that may be causing the issue.
Ghost images are a common issue in laser printers where an image or text from a previous page appears faintly on subsequent pages. The cause of this issue is usually due to toner residue on the drum or rollers, which can be removed by cleaning the toner drums and rollers. References: Study Guide Section 4.6 - Printer technologies

Explanation
A line-of-sight wireless system is a type of wireless communication that requires a clear and unobstructed path between the transmitter and the receiver. This can be achieved by using directional antennas that focus the radio signals in a narrow beam. A line-of-sight wireless system can provide a stable network connection between two buildings that are within the range and visibility of each other.
However, before purchasing and installing a line-of-sight wireless system, one of the factors that needs to be considered is the regulatory power limits. The power limit is the maximum amount of radio frequency (RF) energy that a transmitter can emit. Different countries and regions have different regulations and standards for the allowable power levels of wireless devices. Exceeding the power limit can cause interference with other wireless services, such as aviation, radio, television, etc. It can also pose health and safety risks to humans and animals.
Therefore, a technician should check the local laws and regulations for the power limits of the wireless system before buying and installing it. The technician should also use a proper tool to measure the actual power output of the transmitter and adjust it accordingly. The technician should also ensure that the transmitter and receiver are aligned properly and have a clear line of sight without any obstacles.
The other options are not relevant to the line-of-sight wireless system. The IP address range is a set of numerical identifiers that are assigned to devices on a network. It does not affect the physical transmission of wireless signals. The SSID broadcast is a feature that allows a wireless network to announce its name and availability to nearby devices. It does not affect the stability of the network connection between two buildings.
The firewall rules are a set of policies that control the incoming and outgoing traffic on a network. They do not affect the line-of-sight wireless system.
References:
Wireless line-of-sight, non-line-of-sight, beyond-line-of-sight propagation Point-to-point Wi-Fi bridging between buildings-the cheap and easy way How Does Wireless Internet, or Line of Sight Internet Work?
Line-of-Sight Transmission - Engineering LibreTexts
What is Line of Sight (LoS)? - Definition from Techopedia

If the touch-screen features on a Windows device have stopped working, a technician should check the Tablet/PC settings. The Tablet/PC settings contain options for configuring the touch-screen features on a Windows device. By checking the Tablet/PC settings, the technician can ensure that the touch-screen features are enabled and configured correctly.
If the touch-screen features on a Windows device have stopped working, a technician should check the Tablet/PC settings. The touch-screen settings may have been disabled or there may be a driver issue that needs to be resolved. References: CompTIA A+ Certification Exam Guide, pg. 536

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)