The correct answer is: A. MSAV
MSAV (Microsoft Anti-Virus) is a DOS-based antivirus program that was developed by Microsoft. It was first released in 1988 and was the first antivirus program to be included with Microsoft Windows. MSAV scans memory and disk for viruses and can remove them if found.
B. DEFRAG is a DOS-based disk defragmentation program that was developed by Microsoft. It was first released in 1991 and is used to defragment the hard disk drive. Defragmentation rearranges the data on the hard disk drive so that it is stored in contiguous blocks, which improves the performance of the hard disk drive.
C. SCANDISK is a DOS-based disk checking program that was developed by Microsoft. It was first released in 1987 and is used to check the hard disk drive for errors. SCANDISK can repair errors on the hard disk drive if found.
D. VSAFE is a DOS-based virus scanner that was developed by Microsoft. It was first released in 1988 and is used to scan memory and disk for viruses. VSAFE can remove viruses if found.
E. None of the above.