Explanation
It is common for companies to place a data cap on the devices they provide to their employees, to control costs. If a user has exceeded the data cap, the phone may no longer allow internet browsing over a cellular connection. This is usually because the cellular data usage has exceeded the allotted amount for the particular plan the device is on, and the service provider has temporarily suspended the data connection.
It is unlikely that the child accidentally connected to a neighbor's WLAN because this would not affect the cellular data connection. Similarly, it is unlikely that the company's group policy has disabled the device, as this would likely affect all devices under the same policy. If the device's plan has been unpaid, the service provider would likely temporarily suspend all services, not just the cellular data connection.

The technician should check the level of network utilization to determine if there is an excessive amount of traffic that may be causing the slow access to the network fileshare. This can be done using network monitoring tools to track the amount of data being transmitted on the network. Reference: CompTIA A+ Certification Exam Objectives 1001, 2.9

When installing a wireless point-to-point connection between two buildings, the technician should consider the allowable limits for transmit power, which vary depending on the country or region. Exceeding these limits could interfere with other wireless devices or violate regulations. NFC protocol data rate, RFID frequency range, and Bluetooth version compatibility are not relevant for a wireless point-to-point connection.

NVMe (Non-Volatile Memory Express) is an interface protocol built especially for Solid State Drives (SSDs) to utilize the high-speed PCIe bus in computers. M.2 is a form factor that is commonly used for NVMe SSDs due to its compact size and direct connection to the PCIe interface, which is ideal for laptops. The 2.5" and
3.5" form factors are more commonly associated with SATA drives, and SD is a form factor used for removable flash memory cards, not for internal storage solutions like NVMe SSDs.
References:
* CompTIA A+ Core 1 Exam Objectives Section 3.3: Given a scenario, select and install storage devices.

DHCP (Dynamic Host Configuration Protocol) is a network service that automatically assigns IP addresses and other configuration parameters to devices that request them. DHCP simplifies the management of IP addresses and avoids conflicts and errors67. An APIPA (Automatic Private IP Addressing) is a feature of Windows that assigns a default IP address in the range of 169.254.x.x to a device when it cannot obtain a valid IP address from a DHCP server. An APIPA indicates that there is a problem with the DHCP service or the network connectivity between the device and the DHCP server89. Therefore, the technician should investigate the DHCP service first to check if it is running, configured correctly, and has enough available IP addresses to assign. The other services are not directly related to the IP address assignment. RADIUS (Remote Authentication Dial-In User Service) is a protocol that provides centralized authentication, authorization, and accounting for network access10. AAA (Authentication, Authorization, and Accounting) is a framework that controls the access and usage of network resources11. DNS (Domain Name System) is a service that resolves domain names into IP addresses12.
Reference
6: What is DHCP (Dynamic Host Configuration Protocol)? - Definition from WhatIs.com
7: How DHCP works - Windows Server | Microsoft Docs
8: What is APIPA (Automatic Private IP Addressing)? - Definition from WhatIs.com
9: How to Fix an IP Address Conflict
10: What is RADIUS (Remote Authentication Dial-In User Service)? - Definition from WhatIs.com
11: What is AAA (authentication, authorization, and accounting)? - Definition from WhatIs.com
12: What is DNS (Domain Name System)? - Definition from WhatIs.com