When an external touch screen exhibits flickering without registering input on a presentation laptop, the first troubleshooting step should be to check the cables connecting the touch screen to the laptop. This includes ensuring that the cables are securely connected, undamaged, and are the correct type for transmitting both video and touch input data. Faulty, loose, or incorrect cabling can lead to issues like flickering and unregistered inputs.
References:
* CompTIA A+ Core 1 (220-1101) Exam Objectives, particularly the sections dealing with peripheral devices and troubleshooting connectivity and performance issues related to external devices like touch screens.
* Basic troubleshooting principles for peripheral devices, emphasizing the importance of verifying physical connections and cable integrity when encountering issues with device functionality.

Toner Probe Many cable testers also incorporate the function of a toner probe, which is used to identify a cable from within a bundle. This may be necessary when the cables have not been labeled properly. The tone generator is connected to the cable using an RJ45 jack and applies a continuous audio signal on the cable. The probe is used to detect the signal and follow the cable over ceilings and through ducts or identify it from within the rest of the bundle.

When a laptop screen is not displaying on a conference room TV despite being connected to a wireless HDMI dongle, the issue is often related to the TV being set to the wrong input source. Since the in-room computer's desktop is displayed, it suggests the TV is currently set to the input source used by the in-room computer.
Changing the TV's input source to the one associated with the wireless HDMI dongle connected to the user's laptop is the simplest and most direct approach to resolve the issue. This does not involve adjusting network settings or hardware configurations but rather selecting the correct input source through the TV's input selection menu.
References: This solution is aligned with best practices for troubleshooting display connectivity issues, which emphasize checking and adjusting input sources on the display device as a first step.

Domain Name System (DNS) is an Internet service that translates domain names (e.g., its.umich.edu) into IP addresses. Dynamic Host Configuration Protocol (DHCP) is a protocol for automatically assigning IP addresses and other configurations to devices when they connect to a network.

Two-factor authentication (2FA) is a security process that requires users to provide two different authentication factors to verify their identity. This means that in addition to providing something they know (such as a password or PIN), they must also provide something they have (such as a smart card or token) or something they are (such as a fingerprint or retinal scan).
In this case, the correct answer would be C. Password/thumbprint. This option meets the requirement for two-factor authentication because it combines two different types of authentication factors: something the user knows (the password) and something the user is (the thumbprint). The other options do not meet the requirement for 2FA because they either use only one type of authentication factor (A and D) or use two instances of the same type of factor (B).