Answer:
'\' is the correct answer for the above question.
Explanation:
In the windows command line '\' symbol is used for the directory. In any computer system, the hard disk is a large set of memory. so the user needs to partition to make one or more part and that part is known as a drive.
The drive is the most important part of the system so it is uniquely identified on the command line by the help of '\' symbol.
Just for example if a user wants to open the D drive in a window command line by pressing D: then the command line shows--
D:\>
Hence '\' is used to refer the directory in the windows command line. Hence the answer is '\'.