Which of the following devices extends the range of a network?

An access point (AP) is a networking device that creates a wireless local area network (WLAN). It connects to a wired network infrastructure (like a router or switch) and broadcasts a Wi-Fi signal, allowing wireless devices to connect. By strategically placing APs, network administrators can extend the physical range and coverage of the network far beyond the reach of a single router. This is the primary method for providing wireless connectivity across large areas such as office buildings, campuses, or public spaces.

A. Modem: A modem's function is to modulate and demodulate signals to connect a local network to an Internet Service Provider (ISP), not to extend the local network's range.
B. Server: A server is a computer that provides data, resources, or services to other computers (clients) on the network; it does not extend the network's physical signal coverage.
C. Host firewall: A host firewall is a software application that runs on a single computer to protect it from unauthorized network traffic; it is a security tool, not a range-extending device. ---

1. Kurose, J. F., & Ross, K. W. (2021). Computer Networking: A Top-Down Approach (8th ed.). Pearson. In Chapter 7, Section 7.2.2, "The 802.11 Architecture," the text explains that multiple access points can be connected to a distribution system (e.g., a wired Ethernet network) to create an Extended Service Set (ESS), which is explicitly designed to extend the coverage area of a wireless network.

2. Tanenbaum, A. S., & Wetherall, D. J. (2011). Computer Networks (5th ed.). Prentice Hall. Chapter 4, Section 4.6.2, "802.11 Architecture and Protocol Stack," describes how an access point functions as a bridge to a wired network and how multiple APs can be linked to form an Extended Service Set to cover a larger geographical area.

3. MIT OpenCourseWare. (2011). 6.02 Introduction to EECS II: Digital Communication Systems, Fall 2011. Lecture 19: Wireless Communication. The lecture materials describe the access point as the central point of a "basic service set" that provides connectivity between wireless clients and the wired network infrastructure, with its placement determining the coverage area.