The correct answer is A.
OBJ-5.3: S.M.A.R.T. is an acronym for Self-Monitoring and Repair Tool. It is a feature in all modern magnetic hard drives (non-SSD drives) that monitors the hard drive to ensure it performs properly. S.M.A.R.T. can detect when the failure of a drive is imminent and can alert the user so that they can backup the drive before a complete failure occurs. If your hard drive produces a S.M.A.R.T. failure, you should immediately backup the drive. Once a backup has been completed, you can instead focus on repairing the drive using chkdsk.