A router is a device that connects one or more networks, such as a home or small office network, to the internet. It allows multiple devices to share a single internet connection and provides network address translation (NAT) to enable communication between the devices on the local network and the internet. A hub, Ethernet gateway, or wireless access point does not provide this functionality.
A router is the most likely device to be used to connect one or more devices to the internet in a SOHO. A router can provide network address translation (NAT), firewall protection, and other features that are important for securing and managing a network. References: CompTIA A+ Certification Exam Guide, pg. 355

Explanation:
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NFC (Near Field Communication) is a wireless communication technology that is commonly used for contactless payments, mobile payments, and other mobile transactions. It allows two devices to communicate with each other when they are placed in close proximity.
Contactless payments commonly use NFC (Near Field Communication). NFC is a wireless communication technology that allows two devices to communicate with each other when they are in close proximity. Contactless payments use NFC to enable customers to make payments by simply tapping their contactless card or mobile device on a payment terminal.

The first thing that the technician should do to diagnose the issue is
A) Check the keyboard layout.
The keyboard layout is the arrangement of the keys and symbols on the keyboard, which can vary depending on the language, region, or standard. If the keyboard layout is not set correctly, it can cause the keys to produce different characters than expected. For example, if the keyboard layout is set to French, pressing the key for @ will produce a instead.
To check and change the keyboard layout, the technician can follow these steps:
* On Windows 10, click on the Start menu and select Settings.
* Click on Time & Language and then on Language.
* Under Preferred languages, click on the current language and then on Options.
* Under Keyboards, check if the keyboard layout matches the physical keyboard. If not, click on Add a keyboard and select the correct layout. Alternatively, click on Remove to delete any unwanted layouts.
* To switch between keyboard layouts, use the shortcut Windows key + Space bar.
Checking the keyboard layout can help identify and fix the issue quickly and easily, without requiring any hardware or software changes. Therefore, it is the best first step to diagnose the issue.
Reference:
1: How to change your keyboard layout on Windows 10 PC | Windows Central
2: How to type French accents on a PC - FrenchCrazy

Explanation
SAS (Serial Attached SCSI) is an interface type that supports high-speed data transfer and high-performance hard drives, such as 15,000rpm drives. SAS drives are commonly used in servers that require fast access and reliability. IDE (Integrated Drive Electronics), eSATA (external SATA), and SATA (Serial ATA) are not suitable for 15,000rpm drives, as they have lower speed and performance.
Reference: [CompTIA A+ Core 1 (220-1101) Certification Study Guide], page 22.