The correct answer is A. Detailed guides for resolving common issues, because effective deployment documentation must support ongoing troubleshooting and support, not just initial installation. Including known issues and resolution steps allows future technicians to resolve problems efficiently and consistently.
According to the Quentin Docter - CompTIA A+ Complete Study Guide, high-quality technical documentation should include error conditions, common failure points, and step-by-step remediation procedures. This information significantly reduces mean time to resolution (MTTR) and improves service quality.
The Travis Everett & Andrew Hutz - All-in-One Exam Guide emphasizes that help desk documentation should evolve over time, incorporating lessons learned from previous incidents. Troubleshooting guides turn deployment documentation into a practical reference rather than a static record.
The Mike Meyers / Mark Soper Lab Manual further clarifies that email logs are informal and unstructured, vendor contact information is supplementary, and end-user manuals are not intended for technical troubleshooting. None of these provide actionable guidance for technicians resolving future issues.
Because the goal is to ensure long-term supportability and effective troubleshooting, the most important inclusion is detailed guides for resolving common issues, making A the correct answer.

Remote wipe is the best option to prevent unauthorized access to data when a mobile device is lost or stolen- especially if the user is unaware of the loss. It allows administrators or mobile device management (MDM) systems to remotely erase all data on the device, rendering it unusable for unauthorized users.
A). Encryption protects the data, but if the device remains powered and logged in, it may still be accessible.
C). Geofencing can restrict features based on location but does not erase data.
D). Facial recognition helps secure access but can be bypassed in some cases or fail in practical situations.
Reference:
CompTIA A+ 220-1102 Objective 2.2: Compare and contrast security measures and tools.
Study Guide Section: Mobile device security (remote wipe, lockout, MDM tools)

If the phone works on Wi-Fi but not off Wi-Fi, the most likely issue is that cellular data is disabled (or restricted). This aligns directly with the CompTIA A+ objective language for mobile troubleshooting, which explicitly includes "wireless/cellular data network (enable/disable)." After travel, users often enable airplane mode or disable cellular data to avoid roaming charges, and sometimes forget to re-enable it.
Quentin Docter's mobile connectivity discussion repeatedly distinguishes Wi-Fi access from cellular connectivity and treats cellular settings as a primary area to verify when Internet access is not available away from Wi-Fi. While data caps/limits could throttle service, they usually don't make all non-Wi-Fi browsing and email impossible immediately. VPN issues might block some access, but the simplest "most likely" resolution based on the symptom is re-enabling cellular data. Reinstalling the SIM is possible, but again not the first, most likely fix given the scenario framing. Therefore, Enable cellular data (A) is correct.

Before deploying an application update broadly, best practice is to test it in an isolated environment to avoid breaking production systems. The All-in-One guide defines sandbox testing clearly: "a sandbox is a place where you can experiment without messing up the primary system," typically a virtualized environment, and it "entails checking out new and updated applications without putting the systems and data you depend on at risk." That directly aligns with rolling out a new application update across the organization.
Mike Meyers' Lab Manual repeats the same concept: sandbox testing uses an isolated environment and snapshots to test changes safely before production deployment. It's positioned as a documented business process within change-management best practices, reinforcing why it comes early-before impact spreads.
A backup/rollback plan is important too, but the question asks for the first step when applying a new update to everyone. Testing first helps identify compatibility issues, installation failures, and side effects early-so you don't deploy a bad update at scale. Therefore, Sandbox testing (C) is correct.

Open Ethernet ports in a public-facing area create a direct, high-trust entry point into the internal network.
The most efficient fix is to remove that exposure by disabling the lobby ports and moving untrusted users to a segmented guest network. Quentin Docter explains why disabling unused/unauthorized access points matters:
"Ports on a switch, router, or firewall not in use present an open door for an attacker to enter and should be disabled or disconnected." That directly supports disabling lobby switch ports that shouldn't be available to external users.
He also describes guest network isolation: guests "never need to connect to the organization's servers and internal systems," so a guest SSID should be created that "isolates guest traffic from production traffic." This is exactly what option B accomplishes: it prevents contractors from gaining internal wired access while still providing Internet access through a controlled guest network.
WPA3 (A) only improves Wi-Fi encryption; it doesn't stop wired port access. Monitoring traffic (C) is reactive. Signage (D) is weak administrative control compared to disabling the ports.