Which of the following chmod commands would make the file "file.txt" readable by the owner, writable by other users in the file's group, and executable by the world? chmod 421 file.txt chmod 042 file.txt chmod 777 file.txt chmod 111 file.txt Question 6 1 pts Which of the following statements is correct about shells: All of the above Shells show output to the user Shells accept command input from user Shells can run external commands