Operating System is like a

In the context of Computer Science and Disk Operating System (DOS), an Operating System (OS) can be compared to Option C: Government. This comparison reflects the role of an OS in managing and governing the computer's hardware and software resources, much like a government oversees and manages a country's resources and operations.

Option A, "Parliament," and Option B, "Secretary," are not accurate comparisons for an Operating System.
Option D, "None of the above," is not applicable as Option C is the correct comparison.

Therefore, the correct answer is Option C: Government.