The command used to compare the files is known as

The correct answer is: B. cmp

The command used to compare the files is known as cmp. It is a command-line utility for comparing two files. It prints the lines that are different between the two files, and the number of lines that are different.

The other options are incorrect.

• Option A, comp, is a command-line utility for compressing files.
• Option C, do, is a command-line utility for running shell scripts.
• Option D, ccp, is a command-line utility for copying files.
• Option E, None of the above, is incorrect because it is not a valid option.