When was MS Windows operating system introduced?
A. 1975
B. 1985
C. 1995
D. 2000
Answer: Option B
Solution (By Examveda Team)
Microsoft Windows is a group of several graphical operating system families, all of which are developed, marketed, and sold by Microsoft.Microsoft introduced an operating environment named Windows on November 20, 1985, as a graphical operating system shell for MS-DOS in response to the growing interest in graphical user interfaces (GUIs).
Source : wikipedia.org

again incorrect......this answer is 1985...make some updation your answers are not correct