⟩ A user executes the following command successfully $ chmod +x file1.txt Which of the following is true of the output of this command? a) The command results in adding execute permission to the user who ran this command b) The command results in adding execute permission for the owner of the file c) The command results in an error since the file is not an executable file d) The command results in adding execute permission for all users (i.e., user,group & others)