The correct answer is D. cron.
Cron is a time-based job scheduler in Unix-like operating systems. Cron enables users to schedule jobs (commands or shell scripts) to run periodically at fixed times, dates, or intervals.
Vi is a text editor that is often used on Unix-like operating systems. It is a modal editor, which means that it has different modes for different tasks. The most common mode is command mode, which is used to enter commands. Other modes include insert mode, which is used to insert text, and visual mode, which is used to select text.
Outlook is a personal information manager from Microsoft. It is used to manage email, contacts, calendars, tasks, and notes.
Scheduler is a Windows program that can be used to schedule tasks to run at a specific time or interval.
E is not a valid option.