An MX (Mail Exchange) record specifies the mail server responsible for receiving email for a domain.
* Why Not A (CNAME): CNAME is used for domain aliasing, not for email delivery.
* Why Not B (SRV): SRV records are used to locate specific services, not mail servers.
* Why Not D (SOA): SOA records provide domain information but do not handle email.
CompTIA A+ Exam Reference: Core 1 (220-1101), Section 2.6, DNS record types.

The most likely action that would resolve the issue is to clean the keyboard. Sometimes dust, hair, and other debris can affect keyboard functionality. The technician can try to clean the keyboard as much as possible, which may be enough to get the keyboard back in working order

A VPN (Virtual Private Network) is the technology that allows a home PC to connect securely to a company's network over the internet. It extends a private network across a public network, enabling users to send and receive data as if their computing devices were directly connected to the private network. This makes VPNs ideal for remote work and accessing company resources securely from a home PC.
References:
* CompTIA A+ Core 1 (220-1101) Exam Objectives, specifically sections that cover networking concepts and technologies, including remote access methods and network security protocols such as VPNs.
* Understanding of network security practices and remote access technologies, focusing on how VPNs create secure connections over the internet for remote users to access corporate networks.

When a new GPU is installed and results in lower screen resolution and picture quality, it's often because the appropriate OEM (Original Equipment Manufacturer) drivers for the GPU have not been installed. Without these drivers, the operating system may revert to generic drivers that do not fully support the GPU's capabilities, leading to suboptimal performance. Installing the correct OEM drivers should resolve the issue and allow the GPU to function at its intended performance level.
References:
* CompTIA A+ Core 1 (220-1101) Exam Objectives, particularly those relating to the installation and configuration of hardware components like GPUs, and the importance of installing the correct device drivers for optimal hardware performance.
* General knowledge of hardware installation and the role of device drivers in ensuring hardware components such as GPUs operate correctly within a system.

A firewall is a network device that performs stateful packet inspection, which means it analyzes incoming and outgoing network traffic based on predefined rules and filters, and allows or blocks packets based on their source, destination, protocol, port, or content. A firewall can enhance security by preventing unauthorized access, blocking malicious traffic, enforcing policies, and logging events. A firewall can be hardware-based or software-based, or a combination of both. Reference: https://www.comptia.org/training/books/a-core-1-220-
1101-study-guide (page 78)