When you start your computer, Windows operating system reports that the hard disk drive has bad sectors. What will be your first step in resolving this issue?

Running FORMAT erases all data on the drive without addressing the underlying physical bad sectors, making it destructive and entirely inappropriate as a first troubleshooting step.

Replacing the data cable addresses connectivity or signal-integrity errors between the drive and the motherboard, not physical bad sectors on the disk platters themselves.

DEFRAG rearranges file fragments to improve read/write performance by reducing fragmentation but does not scan for, identify, or repair bad sectors.

SCANDISK with the Thorough option performs both a logical check of the file system and a physical surface test of every sector on the disk, identifying bad sectors and marking them so the operating system will not attempt to write data there. This is the appropriate first response to a bad sector report because it diagnoses the scope of the problem and attempts recovery without destroying existing data.