Ransomware is a type of malware that encrypts the user ' s files and demands a payment (ransom) for the decryption key. When a user receives a message stating that their files are encrypted and cannot be accessed, ransomware is the most likely cause. The attacker's goal is to hold the data hostage until the victim pays to restore access.
A). Keylogger records keystrokes and doesn't encrypt files.
C). Phishing is a social engineering tactic to gather credentials, not to encrypt data.
D). Cryptominer uses system resources to mine cryptocurrency, not encrypt files.
Reference:
CompTIA A+ 220-1102 Objective 2.3: Compare and contrast common types of malware and threats.
Study Guide Section: Ransomware behavior and user impact

Device encryptionensures that even if someone bypasses biometrics or has physical access to the phone, they cannot read the stored data without the encryption key.
FromQuentin Docter - CompTIA A+ Complete Study Guide:
"Encryption is the most effective way to protect data at rest. Even if the device is lost or stolen, encryption ensures the data remains inaccessible without the correct key or passcode."

That browser warning with an "Advanced Options" bypass is a classic indicator of a certificate trust problem (expired, self-signed, wrong hostname, or untrusted CA). Quentin Docter explains that when "an untrusted SSL certificate is encountered, the web browser will alert you that the SSL certificate is not valid," and the address bar may show "Not secure" even if you click through. Since this is an internal application, the correct fix is to ensure the site presents a valid certificate chain trusted by clients-i.e., install a proper SSL/TLS certificate (and ensure it matches the hostname). Docter also describes HTTPS (HTTP over SSL) and notes it uses PKI certificates to validate and encrypt communication.
Mike Meyers' material reinforces that browsers rely on trusted root CAs and warns users when certificates are
"expired" or not trusted. The All-in-One guide similarly states that public keys are delivered as digital certificates signed by a trusted CA, and certificate warnings often mean the site is misconfigured or potentially compromised.
Therefore, the technician should install a proper SSL/TLS certificate for the site (B).

Azero-day vulnerabilitydemands an emergency change to quickly secure the system, even if downtime is needed.
FromMike Meyers' Lab Manual:
"Emergency changes bypass standard scheduling to quickly address critical vulnerabilities that pose immediate risks." .

The user needs to deliver a project status presentation to external stakeholders, which implies hosting a meeting with screen sharing, invitations, and attendee management. Quentin Docter defines videoconferencing as screen-sharing software that allows more than one person to share screens and includes
"additional functionality, such as calendar invite, call-in numbers, and attendee management." He lists Microsoft Teams, WebEx, Zoom, and GoToMeeting as examples and states these tools "are often used to present ideas and collaborate between groups of people." That exactly matches presenting to external stakeholders.
The other options don't fit the requirement: WinRM is a Windows remote management protocol (administration, not presentations), RMM is used by IT providers to manage many systems remotely (not stakeholder presentations), and secure file transfer is for moving files rather than delivering a live presentation. Since videoconferencing platforms commonly provide screen sharing, chat, and meeting controls designed for external audiences, Videoconferencing (C) is the correct software type.