The command grep "non [-] disclosure" legalfile matches the lines in the file that contain the pattern non [-] disclosure, where the brackets indicate a character class that matches either a space or a dash. Therefore, the lines that contain non-disclosure or non - disclosure are matched by the command, while the line that contains disclosure only is not matched. The file has two lines that contain non-disclosure, so the correct answer is E. non-disclosure and non-disclosure Only. References:

grep - IBM

Character Classes and Bracket Expressions - GNU