Disk copy command in DOS is used to A. Copy a file B. Copy contents of one floppy disk to another C. Copy contents of CD-ROM to another D. All of the above

The correct answer is: D. All of the above

The disk copy command in DOS is used to copy a file, copy contents of one floppy disk to another, and copy contents of CD-ROM to another.

The syntax for the disk copy command is:

diskcopy source destination

where:

• source is the name of the disk that you want to copy from.
• destination is the name of the disk that you want to copy to.

For example, to copy the contents of a floppy disk in drive A to a floppy disk in drive B, you would use the following command:

diskcopy a: b:

To copy a file from a floppy disk in drive A to a file on your hard drive, you would use the following command:

diskcopy a:\filename c:\

To copy the contents of a CD-ROM to a floppy disk, you would use the following command:

diskcopy /d a: b:

The /d switch tells the disk copy command to copy the contents of the CD-ROM, including the hidden files and folders.

I hope this helps!