正解:B
Time Machine is the built-in backup feature for macOS that allows users to back up their system automatically. It continuously backs up everything on the Mac, including files, applications, system files, and settings, allowing users to restore their system to a previous state if needed. Time Machine operates by creating hourly backups for the past 24 hours, daily backups for the past month, and weekly backups for all previous months. Other options like "Mission Control" help in organizing windows, while "System Restore" is a feature more common in Windows operating systems, not macOS.
Reference:
Apple Support: Use Time Machine to back up or restore your Mac
CompTIA A+ Study Guide - Backup and Recovery Concepts in macOS (Whizlabs)