IBM released its first PC in 1981. Can you name the operating system which was most popular at that time? A. MS-DOS B. PC-DOS C. OS/360 D. CP/M E. None of the above

The correct answer is A. MS-DOS.

MS-DOS (Microsoft Disk Operating System) was a family of operating systems developed and marketed by Microsoft for personal computers. MS-DOS was the most popular operating system for IBM PC-compatible personal computers from the late

1980s until the mid-1990s.

PC-DOS was a licensed version

of MS-DOS developed by Microsoft for IBM. It was the default operating system for IBM PCs and compatible computers from 1981 until 1995.

OS/360 was a family of operating systems developed by IBM for mainframe computers. It was the first operating system to support virtual memory and multiprogramming.

CP/M (Control Program/Monitor) was an operating system for microcomputers developed by Gary Kildall’s Digital Research. It was the most popular operating system for microcomputers in the early 1980s.

E. None of the above is not the correct answer.