Explanation
Application virtualization is a technique that allows an application to run on a computer without being installed or affecting other applications on the system. Application virtualization creates a virtual environment for the application that isolates it from the underlying operating system and hardware. This way, the technician can verify the application deployment will not affect other legacy applications on the end users' computers.

Explanation
A hotspot is a wireless access point that provides internet access to devices that are connected to it. The technician can use a hotspot to check if the laptop's wireless NIC is functional by connecting the laptop to the hotspot and then trying to browse the internet. If the laptop is able to browse the internet, then the wireless NIC is functional.
Near-field communication (NFC) is a wireless technology that allows two devices to communicate with each other when they are in close proximity. NFC is not typically used to check if a wireless NIC is functional.
An Ethernet tap is a device that is used to monitor network traffic. An Ethernet tap is not typically used to check if a wireless NIC is functional.
A spectrum analyzer is a device that is used to measure the frequency spectrum of a signal. A spectrum analyzer is not typically used to check if a wireless NIC is functional.
Therefore, the correct answer is A. Hotspot.

Explanation
ADF/flatbed scanner would most likely be used to obtain electronic images of a large number of printed documents. References: CompTIA A+ Certification Exam Guide, Exam 220-1001, Page 351

The clicking sound is the sound of a damaged disk in the HDD
A clicking sound from a hard disk drive typically indicates a mechanical failure, such as the read/write head hitting a physical obstruction or a problem with the disk motor. This can cause the drive to fail to initialize or not be recognized by the system during booting.