Full form of MS-DOS is

Answer: Option C

In Disk Operating System (DOS), the full form of MS-DOS is Option C: Micro Soft Disk Operating System. MS-DOS was developed by Microsoft Corporation as a command-line operating system for IBM-compatible personal computers.

Option A, "Micro System Disk Operating System," and Option B, "Micro Simple Disk Operating System," are incorrect and not the correct full forms of MS-DOS.
Option D, "Micro Sort Disk Operating System," is also incorrect.

Therefore, the correct answer is Option C: Micro Soft Disk Operating System.