Final answer:
Operating system-specific security logs track and record security-related events, including login attempts and file access permissions on computers.
Step-by-step explanation:
The log that can provide a cyber technician with the computer's attempted logins or denial when an employee attempts to access a file on an Apple iMac is B. Operating system-specific security logs. These logs are designed to track and record various security-related events on the computer, such as successful and failed login attempts, as well as file access permissions and denials. Operating system security logs are crucial for monitoring and ensuring compliance with company policies regarding computer and data usage.