An IP address in the 169.254.x.x range indicates the device has assigned itself an APIPA address (Automatic Private IP Addressing). This happens when the device is configured to obtain an IP address automatically but cannot reach a DHCP server to receive a valid IP configuration for the local network. With an APIPA address, the device can sometimes communicate only with other devices in the same 169.254.x.x range on the local link, but it typically will not have a correct default gateway or DNS server settings. Without a valid gateway, the device cannot route traffic to the internet, which explains why it cannot access internet websites.
Option C is therefore the most likely cause: the DHCP assignment cannot be obtained due to issues such as a disconnected network cable, disabled Wi-Fi, DHCP server outage, VLAN misconfiguration, or a blocked DHCP request/response on the network.
Option B (DNS failure) could prevent name resolution, but it would not by itself cause an APIPA address.
Option A suggests a static configuration problem, yet APIPA usually appears when the device is set to DHCP, not static. Option D could also break internet access, but it would not specifically result in a 169.254 address on the client.

To ensure a workstation always receives the same IP address while still using DHCP, the correct method is to configure a DHCP reservation. A reservation "combines" two key pieces: the workstation's MAC address (hardware address) and a specific IP address within the DHCP scope. When the workstation requests an address, the DHCP server matches the request to the stored MAC address and consistently assigns the reserved IP each time the device connects. This provides the benefits of DHCP (central management, consistent options like gateway/DNS, easier changes) while giving the workstation a predictable IP, which is often needed for management, monitoring, or firewall rules.
Creating a new scope is used to define an address pool and options for an entire subnet, but it does not guarantee one device always gets the same IP. NAT translates private IPs to public IPs and is unrelated to consistent DHCP assignments for a specific workstation. APIPA automatic private IP addressing 169.254.x.x occurs when DHCP fails and is not a controlled way to ensure a consistent, usable network address.
Therefore, assigning a reservation is the correct answer.

A DHCP reservation binds a specific MAC address to an IP address so the device always receives the same IP from the DHCP server. This ensures network devices like printers maintain consistent connectivity and availability even when the IP pool is low.
Reference: "CompTIA A+ Complete Study Guide" by Quentin Docter - Chapter 18, page 1252.

A switch is the device that primarily forwards traffic based on MAC addresses and is used to connect devices within the same local network. It operates at Layer 2 (Data Link) of the OSI model. When a switch receives an Ethernet frame, it reads the source MAC address and records it in its MAC address table along with the port it arrived on. Then, when the switch needs to send a frame to a destination, it looks up the destination MAC address in that table and forwards the frame only out the correct port. This makes switching efficient and reduces unnecessary traffic compared to older hub-based networks. In CompTIA A+ Core 1, recognizing that MAC-based forwarding is a key switch function is essential.
A router forwards traffic based on IP addresses at Layer 3 and is used to connect different IP networks or VLANs. A modem converts signals for ISP connectivity (e.g., cable/DSL/fiber handoff) and does not forward frames by MAC table learning. A firewall filters traffic based on security rules and is not primarily a MAC- forwarding device. Therefore, the best answer is Switch.

2.4GHz Wi-Fi signals have better penetration through walls and other obstacles compared to 5GHz and
6GHz. Lower frequency waves (like 2.4GHz) travel farther and are less absorbed by physical barriers.
From the CompTIA A+ 220-1101 Official Study Guide, Objective 2.5 - Compare and contrast wireless networking protocols:
"The 2.4GHz frequency band offers greater range and better penetration through walls and obstacles than higher frequencies like 5GHz and 6GHz. Higher frequencies provide faster speeds but are more easily absorbed by walls." NFC (Near Field Communication) is not a Wi-Fi technology and works only over very short distances (a few centimeters).
Verified Source:
CompTIA A+ Core 1 (220-1101) Official Study Guide, Chapter 2: Wireless Networking CompTIA Exam Objectives 220-1101, Domain 2.5