Which command is used to assign only read permission to all three categories of the file ‘note’? A. chmod go+r note B. chmod a-rw C. chmod ugo=r note D. chmod u+r,g+r,o-x note E. None of the above

The correct answer is D. chmod u+r,g+r,o-x note

The chmod command is used to change the permissions of a file. The first argument is the mode, which is a string of three or four characters. The first character specifies the permissions for the owner of the file, the second character specifies the permissions for the group that owns the file, and the third character specifies the permissions for everyone else. The fourth character is optional and is used to specify special permissions.

The r, w, and x characters represent read, write, and execute permissions, respectively. A plus sign (+) adds a permission, a minus sign (-) removes a permission, and an equals sign (=) sets a permission to the specified value.

In the command chmod u+r,g+r,o-x note, the u indicates that the permissions are being changed for the owner of the file, the g indicates that the permissions are being changed for the group that owns the file, and the o indicates that the permissions are being changed for everyone else. The r indicates that read permission is being added, the g indicates that read permission is being added, and the x indicates that execute permission is being removed.

This command will assign read permission to all three categories of the file ‘note’.