Explanation
A sandbox is a virtualization solution that allows a legacy application to run in an isolated environment without affecting other applications or systems. A sandbox can emulate an older operating system or hardware configuration that is compatible with the legacy software. A hybrid cloud is a combination of public and private cloud services that share data and resources. Infrastructure as a service is a cloud computing model that provides servers, storage, networking, and software over the internet. Public cloud is a cloud computing model that provides services and resources to anyone over the internet. Private cloud is a cloud computing model that provides services and resources to a specific organization or group over a private network.

Explanation
The correct answer is B. Check the power supply wattage rating.
A possible cause of the desktop randomly shutting down during operations is that the power supply is not able to provide enough power for the high-end graphics card. The power consumption of today's graphics cards has increased a lot, and the top models demand between 110 and 270 watts from the power supply1. Therefore, the technician should check the power supply wattage rating and make sure it is sufficient for the graphics card and the rest of the components. Confirming the power supply is grounded, checking whether the power supply is redundant, or confirming the power cables are well connected are not likely to solve this problem.

Explanation
To enable devices to connect to the internet after installing a new router at a small office, the technician should configure DHCP (Dynamic Host Configuration Protocol) on the router. DHCP is a network protocol that automatically assigns IP addresses and other network configuration parameters to devices on a network.
By configuring DHCP on the router, the technician can ensure that all devices on the network are assigned a valid IP address that allows them to connect to the internet.
If all devices have a 169.254.x.x IP address, this suggests that the router is not assigning IP addresses to the devices using DHCP (Dynamic Host Configuration Protocol). Configuring the DHCP settings on the router can enable the devices to receive IP addresses automatically and access the internet. References: CompTIA A+ Certification All-in-One Exam Guide, Tenth Edition, Chapter 14

Explanation
When a user hears one beep on rebooting a machine, and then an error message is displayed, it could indicate that there is a problem with the RAM module or the boot order. The beep sound indicates that the POST process was successful, and the error message indicates that the boot process was unsuccessful. The boot order determines the sequence in which the computer looks for bootable devices. References: CompTIA A+ Certification All-in-One Exam Guide, Tenth Edition by Mike Meyers (Page 693)

Explanation
If the filesystem check shows that all files are accessible and the filesystem is clean, but a hard drive error message persists, it's possible that the hard drive is experiencing S.M.A.R.T. (Self-Monitoring, Analysis, and Reporting Technology) failure. This is a warning system built into hard drives to alert users of potential issues before they become critical. References: CompTIA A+ Certification Exam Core 1 Exam Objectives - 3.3 Given a scenario, troubleshoot mobile device issues