21. The location for subdirectories for local programs and executables for user and administrative commands, is:

A. /usr
B. /tmp
C. /opt
D. /mnt
E. None of the above

22. Which of the following is not a filter command?

A. sort
B. wc
C. grep
D. cat
E. None of the above

23. What command is used to display a file contents in octal form?

A. oct
B. of
C. od
D. cd
E. None of the above

24. What command is used to assign executable permission to all of the files named “report”?

A. chmod ugo + x report
B. chmod u + x report
C. chmod ugo + rw report
D. chmod ugo + r report
E. None of the above

25. What command is used to change the working directory?

A. cdir
B. chdir
C. changedir
D. cd
E. None of the above