You turn on your Mac, and a folder with a question mark appears.

A flashing folder with a question mark indicates that the Mac cannot find an available startup disk containing a working macOS installation. Apple’s documented troubleshooting procedure is to start the Mac in macOS Recovery and open Disk Utility. Disk Utility can then be used to locate the startup storage device and run First Aid to check and repair its file system. Therefore, option D is correct. Apple Diagnostics focuses primarily on identifying hardware faults and is not the first Recovery utility specified for this startup-screen condition. Startup Security Utility manages security policies and boot-security options, while Share Disk allows files to be transferred between Mac computers. If Disk Utility cannot repair or detect the startup disk, additional recovery, reinstallation, erasure, or hardware service may subsequently be required.

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