In a star topology, all devices on a network connect to a central hub or switch, which acts as a common connection point. Ethernet LANs typically use a star topology, with each device connected to a central switch. Reference:
Network+ N10-008 Objectives: 2.2 Explain common logical network topologies and their characteristics.

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.

Asset tags will allow the technician to record changes to new and old equipment when installing multiple UPS units in a major retail store. Asset tags are labels or stickers that are attached to physical assets such as computers, printers, servers, or UPS units. They usually contain information such as asset name, serial number, barcode, QR code, or RFID chip that can be scanned or read by an asset management system or software. Asset tags help track inventory, location, status, maintenance, and ownership of assets. Reference: https://www.camcode.com/asset-tags/asset-tagging-guide/

According to the CompTIA troubleshooting methodology1, testing the theory is the step where the network administrator verifies if the problem is caused by a specific factor or change. This step involves checking the system logs, running diagnostic tools, or performing other tests to confirm or eliminate the possible cause.
Reference:
Troubleshooting Methodology | IT Support and Help Desk | CompTIA1

An ARP request operates at the data link layer of the OSI model. ARP (Address Resolution Protocol) is a protocol that maps IP addresses to MAC addresses on a local area network. It allows devices to communicate with each other without knowing their MAC addresses beforehand. ARP operates at the data link layer (layer 2) of the OSI model, which is responsible for framing and addressing data packets on a physical medium. Reference: https://www.cisco.com/c/en/us/support/docs/ip/routing-information-protocol-rip/13788-3.html