A virtual switch is a software-based switch that connects virtual machines on a hypervisor. A virtual switch can create and manage VLANs, which are logical segments of a network that isolate traffic between different groups of devices. A customer can use virtual switches to segregate the traffic between guests on a hypervisor by creating a separate VLAN for each guest and assigning it to a virtual switch port. Reference: https://www.comptia.org/blog/what-is-a-virtual-switch

A MAC address is a unique identifier assigned to a network interface card (NIC) that allows it to communicate on a physical network layer, such as Ethernet1. An IP address is a logical identifier assigned to a device that allows it to communicate on a network layer, such as IP2.
A technician can use different methods to find the IP address of a device if they know its MAC address. Two of the most common methods are looking at the ARP table and the DHCP leases.
The ARP table is a data structure that stores the mappings between IP addresses and MAC addresses on a device. ARP stands for Address Resolution Protocol, which is a network protocol that enables devices to discover the MAC address of another device based on its IP address3. The ARP table is populated by sending ARP requests and receiving ARP replies, or by using static ARP entries that are manually configured4.
A technician can look at the ARP table of their own device or a nearby device, such as a router or a switch, to find the IP address of a device with a known MAC address. For example, on a Windows device, the technician can use the command arp -a to display the ARP table, and look for the entry that matches the MAC address. On a Cisco device, the technician can use the command show ip arp to display the ARP table, and look for the entry that matches the MAC address.
The DHCP leases are the records of the IP addresses that are assigned by a DHCP server to DHCP clients. DHCP stands for Dynamic Host Configuration Protocol, which is a network protocol that enables devices to obtain IP addresses and other network configuration parameters automatically from a DHCP server. The DHCP leases contain information such as the IP address, the MAC address, the lease duration, and the expiration time of each DHCP client.
A technician can look at the DHCP leases of the DHCP server that serves the network segment where the device with the known MAC address is connected. For example, on a Windows DHCP server, the technician can use the DHCP console to view the DHCP leases, and look for the entry that matches the MAC address. On a Cisco DHCP server, the technician can use the command show ip dhcp binding to view the DHCP leases, and look for the entry that matches the MAC address.
The other options are incorrect for the following reasons:
C . IP route table is a data structure that stores the routes to different network destinations on a device. It does not store the MAC addresses of the devices on the network.
D . DNS cache is a data structure that stores the mappings between domain names and IP addresses on a device. DNS stands for Domain Name System, which is a network service that translates human-readable domain names into IP addresses. It does not store the MAC addresses of the devices on the network.
E . MAC address table is a data structure that stores the mappings between MAC addresses and switch ports on a switch. It does not store the IP addresses of the devices on the network.
F . STP topology is a network design that uses the Spanning Tree Protocol (STP) to prevent loops and create a loop-free logical topology on a switched network. It does not store the IP addresses or the MAC addresses of the devices on the network. Reference:
1: MAC address - Wikipedia
2: IP address - Wikipedia
3: Address Resolution Protocol - Wikipedia
4: How ARP Works
5: How to Use the Arp Command in Windows
6: show ip arp
7: Dynamic Host Configuration Protocol - Wikipedia
8: DHCP Lease
9: View DHCP Leases
10: show ip dhcp binding
11: Routing table - Wikipedia
12: Domain Name System - Wikipedia
13: DNS cache - Wikipedia
14: MAC address table - Wikipedia
15: Spanning Tree Protocol - Wikipedia

802.11a/b/g/n/ac wireless networks operate in two frequency ranges: 2.4 GHz and 5 GHz. The 5 GHz frequency range supports more channels than the 2.4 GHz frequency range, making it a better choice for high-density wireless networks.

Channel overlap occurs when two or more wireless access points (APs) use the same or adjacent frequency channels within the same area12. This can cause interference and degradation of the wireless signal quality, resulting in increased latency and packet drops for the Wi-Fi-connected devices12.
Channel overlap is one of the most common causes of Wi-Fi performance issues, especially in densely populated areas where there are many wireless networks operating in the same spectrum12. The 2.4 GHz band, which is widely used by Wi-Fi devices, has only three non-overlapping channels (1, 6, and 11) in most regions, making it more prone to channel overlap than the 5 GHz band, which has more non-overlapping channels available12.
To fix channel overlap, network administrators should perform a site survey to identify the existing wireless networks and their channel usage, and then configure their APs to use the least congested or non-overlapping channels12. Alternatively, they can use APs that support automatic channel selection, which can dynamically adjust the channel based on the network conditions12.
The other options are not the most likely reasons for the issue. Distance from the AP can affect the signal strength and quality, but it does not explain why the issue occurred only after the new company moved in3. Bandwidth latency is a measure of the delay in data transmission, which can be affected by various factors such as network congestion, routing, or quality of service, but it is not a cause of the issue itself4. RF attenuation is the loss of signal power due to distance, obstacles, or interference, which can also affect the Wi-Fi performance, but it is not specific to the scenario described in the question5. Network congestion is the state of high demand and low availability of network resources, which can cause latency and packet loss, but it is not necessarily related to channel overlap6. Reference:
1: CompTIA Network+ N10-008 Certification Study Guide, Chapter 4: Wireless Networks, Section 4.4: Wireless Network Troubleshooting7
2: Professor Messer's CompTIA N10-008 Network+ Course Notes, Page 25: Wireless Troubleshooting8
3: CompTIA Network+ N10-008 Certification Study Guide, Chapter 4: Wireless Networks, Section 4.2: Wireless Network Implementations7
4: CompTIA Network+ N10-008 Certification Study Guide, Chapter 2: Network Protocols and Services, Section 2.5: Bandwidth and Latency7
5: CompTIA Network+ N10-008 Certification Study Guide, Chapter 4: Wireless Networks, Section 4.1: Wireless Network Fundamentals7
6: CompTIA Network+ N10-008 Certification Study Guide, Chapter 3: Routing, Section 3.5: Network Congestion7
7: CompTIA Network+ N10-008 Certification Study Guide2
8: Professor Messer's CompTIA Network+ N10-008 Training Course5

Using a bottom-to-top approach means starting from the physical layer and moving up the OSI model to troubleshoot a network problem. Checking for a link light is a physical layer check that verifies the connectivity of the network cable and device. Reference: https://www.professormesser.com/network-plus/n10-007/troubleshooting-methodologies-2/