A Personal Area Network (PAN) is designed to connect devices in close proximity, typically within a few meters, often using wireless technologies like Bluetooth. This allows for the interconnection of smart devices such as smartphones, tablets, and wearables within an individual's personal space. Unlike a Local Area Network (LAN), which covers a larger geographical area such as a home or office building and can support wired and wireless connections, a PAN specifically facilitates wireless connections between personal devices.
References:
* CompTIA A+ Core 1 Exam Objectives Section 2.7: Compare and contrast Internet connection types, network types, and their features.

The correct answer is C. Ethernet.
An Ethernet cable is a type of network cable that is used to connect devices on a local area network (LAN), such as computers, routers, switches, and modems. Ethernet cables have RJ-45 connectors at both ends, which are similar to telephone jacks but larger. Ethernet cables can carry data signals at speeds ranging from 10 Mbps to 10 Gbps, depending on the type and quality of the cable.
A cable modem is a device that connects to a coaxial cable from a cable service provider and provides high-speed internet access. A SOHO router is a small office/home office router that connects to a cable modem or DSL modem and provides network and internet access to multiple devices on a LAN. A SOHO router typically has one WAN port and four LAN ports. The WAN port is used to connect to the cable modem or DSL modem, while the LAN ports are used to connect to computers or other devices on the LAN.
To connect a cable modem to a SOHO router, an Ethernet cable is needed. The Ethernet cable is plugged into the WAN port of the SOHO router and the Ethernet port of the cable modem. This allows the SOHO router to receive an IP address from the cable service provider and share it with the devices on the LAN using network address translation (NAT). The SOHO router also provides firewall and wireless features for the LAN.
The other options are incorrect because they are not suitable for connecting a cable modem to a SOHO router.
FireWire is a type of serial bus that is used to connect devices such as digital cameras, external hard drives, and audio interfaces. FireWire cables have different connectors than Ethernet cables and cannot be used for network communication. Fiber is a type of optical cable that uses light signals to transmit data over long distances. Fiber cables have special connectors that are not compatible with Ethernet ports. Coaxial is a type of copper cable that has a central conductor surrounded by an insulating layer and a braided shield. Coaxial cables are used for cable TV and internet services, but they cannot be directly connected to Ethernet ports without an adapter.
References:
CompTIA A+ Certification Exam: Core 1 Objectives (220-1001)
Installing and Configuring a Cable Modem/DSL Router
Cisco 831 Router and SOHO 91 Router Cabling and Setup Quick Start Guide

Channel configuration (e.g., dual-channel, quad-channel) determines how memory modules communicate with the memory controller. Using matched pairs in dual- or quad-channel setups can significantly increase memory bandwidth, improving performance - especially for gaming and video-intensive tasks.
* Option A (Error correction): ECC RAM is used in servers for reliability, not performance or gaming.
* Option B (RAM voltage): Affects compatibility and overclocking but not bandwidth.
* Option D (Physical size): Refers to module form factor (e.g., DIMM, SO-DIMM) and does not impact bandwidth.
CompTIA A+ Core 1 Exam Objective Reference:
* Objective 3.2: Given a scenario, install RAM types.

The technician has identified the symptoms (slow performance and random pop-ups) and must now establish a theory of probable cause, such as malware or spyware infection. This step aligns with the CompTIA troubleshooting methodology.
* Why Not A (Establish a knowledge base): This is irrelevant at this stage; knowledge bases are used for reference and documentation.
* Why Not C (Establish a new theory and consider escalating): The technician has not yet created or tested a theory, making escalation premature.
* Why Not D (Establish a plan of action): Planning an action occurs after determining the cause of the problem.
CompTIA A+ Exam Reference: Core 2 (220-1102), Section 3.1, troubleshooting methodology.

An ONT, or Optical Network Terminal, is a device that converts fiber network signals from light into electric signals that can be used by a Wi-Fi router. An ONT is an interface between the fiber optic network that carries optical signals and the devices that use electrical signals, such as routers, telephones, or computers. An ONT is similar to a modem for fiber internet, as it allows the devices to communicate with the internet service provider (ISP) and access the internet.
References:
The Official CompTIA A+ Core 1 Student Guide (Exam 220-1101) eBook, page 4-111 What Is an ONT? Optical Network Terminals Explained l Reviews.org2 What Is An ONT & How is it Used in Fiber Networks? - STL Tech3